Broadspectrum substituted oxindole sulfonamide HIV protease inhibitors

ABSTRACT

The present invention concerns the compounds having the formula 
                         
N-oxides, salts, stereoisomeric forms, racemic mixtures, prodrugs, esters and metabolites thereof, wherein R 1  and R 8  each are H, optionally substituted C 1-6 alkyl, C 2-6 alkenyl, C 3-7 cycloalkyl, aryl, Het 1 , Het 2 ; R 1  may also be a radical of formula (R 11a R 11b )NC(R 10a R 10b )CR 9 —; t is 0, 1 or 2; R 2  is H or C 1-6 alkyl; L is —C(═O)—, —O—C(═O)—, —NR 8 —C(═O)—, —O—C 1-6 alkanediyl-C(═O)—, —NR 8 —C 1-6 alkanediyl-C(═O)—, —S(═O) 2 —, —O—S(═O) 2 —, —NR 8 —S(═O) 2 ; R 3  is C 1-6 alkyl, aryl, C 3-7 cycloalkyl, C 3-7 cycloalkylC 1-4 alkyl, or arylC 1-4 alkyl; R 4  is H, C 1-4 alkylOC(═O), carboxyl, aminoC(═O), mono- or di(C 1-4 alkyl)aminoC(═O), C 3-7 cycloalkyl, C 2-6 alkenyl, C 2-6 alkynyl or optionally substituted C 1-6 alkyl;
 
                         
R 5a  and R 5b  is C 2-6 alkenyl, C 2-6 alkynyl, C 3-7 cycloalkyl or C 1-6 alkyl, optionally substituted on one or more atoms; R 5a  and R 5b  may also be hydrogen, aryl, Het 1 , Het 2 ; R 6  is hydrogen or C 1-6 alkyl optionally substituted on one ore more carbon atoms. It further relates to their use as broadspectrum HIV protease inhibitors, processes for their preparation as well as pharmaceutical compositions and diagnostic kits comprising them. It also concerns combinations thereof with another anti-retroviral agent, and to their use in assays as reference compounds or as reagents.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the national stage of Application No.PCT/EP03/50379, filed Aug. 14, 2003, which application claims priorityfrom European Patent Application No. 02078384.1 filed Aug. 14, 2002.

This application claims priority benefit to EP Application EP 02078384.1filed on Aug. 14, 2002, the contents of which are expressly incorporatedby reference herein.

The present invention relates to substituted oxindole sulfonamides,their use as broadspectrum HIV protease inhibitors, processes for theirpreparation as well as pharmaceutical compositions and diagnostic kitscomprising them. The present invention also concerns combinations of thepresent substituted oxindole sulfonamides with another anti-retroviralagent. It further relates to their use in assays as reference compoundsor as reagents.

The virus causing the acquired immunodeficiency syndrome (AIDS) is knownby different names, including T-lymphocyte virus III (HTLV-III) orlymphadenopathy-associated virus (LAV) or AIDS-related virus (ARV) orhuman immunodeficiency virus (HIV). Up until now, two distinct familieshave been identified, i.e. HIV-1 and HIV-2. Hereinafter, HIV will beused to generically denote these viruses.

One of the critical pathways in a retroviral life cycle is theprocessing of polyprotein precursors by aspartic protease. For instance,with the HIV virus the gag-pol protein is processed by HIV protease. Thecorrect processing of the precursor polyproteins by the asparticprotease is required for the assembly of infectious virions, thus makingthe aspartic protease an attractive target for antiviral therapy. Inparticular for HIV treatment, the HIV protease is an attractive target.

HIV protease inhibitors (PIs) are commonly administered to AIDS patientsin combination with other anti-HIV compounds such as, for instancenucleoside reverse transcriptase inhibitors (NRTIs), non-nucleosidereverse transcriptase inhibitors (NNRTIs), nucleotide reversetranscriptase inhibitors (NtRTIs) or other protease inhibitors. Despitethe fact that these antiretrovirals are very useful, they have a commonlimitation, namely, the targeted enzymes in the HIV virus are able tomutate in such a way that the known drugs become less effective, or evenineffective against these mutant HIV viruses. Or, in other words, theHIV virus creates an ever-increasing resistance against the availabledrugs.

Resistance of retroviruses, and in particular the HIV virus, againstinhibitors is a major cause of therapy failure. For instance, half ofthe patients receiving anti-HIV combination therapy do not respond fullyto the treatment, mainly because of resistance of the virus to one ormore drugs used. Moreover, it has been shown that resistant virus iscarried over to newly infected individuals, resulting in severelylimited therapy options for these drug-naive patients. On theInternational AIDS Conference in Paris in July 2003 researchers releasedthat the biggest study so far of resistance to AIDS drugs finds thatabout 10 percent of all newly infected people in Europe havedrug-resistant strains. Smaller tests to determine the spread ofresistance have been done in the high-risk city center of San Francisco.This test showed the highest level of resistance at 27 percent.Therefore, there is a need in the art for new compounds for retrovirustherapy, more particularly for AIDS therapy. The need in the art isparticularly acute for compounds that are active not only on wild typeHIV virus, but also on the increasingly more common resistant HIVviruses.

Known antiretrovirals, often administered in a combination therapyregimen, will eventually cause resistance as stated above. This oftenmay force the physician to boost the plasma levels of the active drugsin order for said antiretrovirals to regain effectivity against themutated HIV viruses. The consequence of which is a highly undesirableincrease in pill burden. Boosting plasma levels may also lead to anincreased risk of non-compliance with the prescribed therapy. Thus, itis not only important to have compounds showing activity for a widerange of HIV mutants, it is also important that there is little or novariance in the ratio between activity against mutant HIV virus andactivity against wild type HIV virus (also defined as fold resistance orFR) over a broad range of mutant HIV strains. As such, a patient mayremain on the same combination therapy regimen for a longer period oftime since the chance that a mutant HIV virus will be sensitive to theactive ingredients will be increased.

Finding compounds with a high potency on the wild type and on a widevariety of mutants is also of importance since the pill burden can bereduced if therapeutic levels are kept to a minimum. One additional wayof reducing this pill burden is finding anti-HIV compounds with goodbioavailability, i.e. a favorable pharmacokinetic and metabolic profile,such that the daily dose can be minimized and consequently also thenumber of pills to be taken.

Another favorable characteristic of an anti-HIV compound is that plasmaprotein binding of the inhibitor has minimal or even no effect on itspotency.

Thus, there is a high medical need for protease inhibitors that are ableto combat a broad spectrum of mutants of the HIV virus with littlevariance in fold resistance. Those protease inhibitors with a goodbioavailability and little or no effect on their potency due to plasmaprotein binding have additional advantages.

Up until now, several protease inhibitors are on the market or are beingdeveloped. One particular core structure (depicted below) has beendisclosed in a number of references, such as, WO 95/06030, WO 96/22287,WO 96/28418, WO 96/28463, WO 96/28464, WO 96/28465 and WO 97/18205. Thecompounds disclosed therein are described as retroviral proteaseinhibitors.

WO 99/67254 discloses 4-substituted-phenyl sulfonamides capable ofinhibiting multi-drug resistant retroviral proteases.

The substituted oxindole sulfonamides of the present invention are foundto have a favorable pharmacological profile. Not only are they activeagainst wild-type HIV virus, but they also show a broadspectrum activityagainst various mutant HIV viruses exhibiting resistance against knownprotease inhibitors.

The present invention concerns substituted oxindole protease inhibitors,having the formula

and N-oxides, salts, stereoisomeric forms, racemic mixtures, prodrugs,esters and metabolites thereof, wherein

-   R₁ and R₈ are, each independently, hydrogen, C₁₋₆alkyl, C₂₋₆alkenyl,    arylC₁₋₆alkyl, C₃₋₇cycloalkyl, C₃₋₇cycloalkylC₁₋₆alkyl, aryl, Het¹,    Het¹C₁₋₆alkyl, Het², Het²C₁₋₆alkyl;-   R¹ may also be a radical of formula

wherein

-   -   R₉, R_(10a) and R_(10b) are, each independently, hydrogen,        C₁₋₄alkyloxycarbonyl, carboxyl, aminocarbonyl, mono- or        di(C₁₋₄alkyl)aminocarbonyl, C₃₋₇cycloalkyl, C₂₋₆alkenyl,        C₂₋₆alkynyl or C₁₋₄alkyl optionally substituted with aryl, Het¹,        Het², C₃₋₇cycloalkyl, C₁₋₄alkyloxycarbonyl, carboxyl,        aminocarbonyl, mono- or di(C₁₋₄alkyl)aminocarbonyl,        aminosulfonyl, C₁₋₄alkylS(O)_(t), hydroxy, cyano, halogen or        amino optionally mono- or disubstituted where the substituents        are each independently selected from C₁₋₄alkyl, aryl,        arylC₁₋₄alkyl, C₃₋₇cycloalkyl, C₃₋₇cycloalkylC₁₋₄alkyl, Het¹,        Het², Het¹C₁₋₄alkyl and Het²C₁₋₄alkyl; wherein R₉, R_(10a) and        the carbon atoms to which they are attached may also form a        C₃₋₇cycloalkyl radical; when L is —O—C₁₋₆alkanediyl-C(═O)— or        —NR₈—C₁₋₆alkanediyl-C(═O)—, then R₉ may also be oxo;    -   R_(11a) is hydrogen, C₂₋₆alkenyl, C₂₋₆alkynyl, C₃₋₇cycloalkyl,        aryl, aminocarbonyl optionally mono- or disubstituted,        aminoC₁₋₄alkylcarbonyloxy optionally mono- or disubstituted,        C₁₋₄alkyloxycarbonyl, aryloxycarbonyl, Het¹oxycarbonyl,        Het²oxycarbonyl, aryloxycarbonylC₁₋₄alkyl,        arylC₁₋₄alkyloxycarbonyl, C₁₋₄alkylcarbonyl,        C₃₋₇cycloalkylcarbonyl, C₃₋₇cycloalkylC₁₋₄alkyloxycarbonyl,        C₃₋₇cycloalkylcarbonyloxy, carboxylC₁₋₄alkylcarbonyloxy,        C₁₋₄alkylcarbonyloxy, arylC₁₋₄alkylcarbonyloxy, arylcarbonyloxy,        aryloxycarbonyloxy, Het¹carbonyl, Het¹carbonyloxy,        Het¹C₁₋₄alkyloxycarbonyl, Het² carbonyloxy,        Het²C₁₋₄alkylcarbonyloxy, Het²C₁₋₄alkyloxycarbonyloxy or        C₁₋₄alkyl optionally substituted with aryl, aryloxy, Het² or        hydroxy; wherein the substituents on the amino groups are each        independently selected from C₁₋₄alkyl, aryl, arylC₁₋₄alkyl,        C₃₋₇cycloalkyl, C₃₋₇cycloalkylC₁₋₄alkyl, Het¹, Het²,        Het¹C₁₋₄alkyl and Het²C₁₋₄alkyl;    -   R_(11b) is hydrogen, C₃₋₇cycloalkyl, C₂₋₆alkenyl, C₂₋₆alkynyl,        aryl, Het¹, Het² or C₁₋₄alkyl optionally substituted with        halogen, hydroxy, C₁₋₄alkylS(═O)_(t), aryl, C₃₋₇cycloalkyl,        Het¹, Het², amino optionally mono- or disubstituted where the        substituents are each independently selected from C₁₋₄alkyl,        aryl, arylC₁₋₄alkyl, C₃₋₇cycloalkyl, C₃₋₇cycloalkylC₁₋₄alkyl,        Het¹, Het², Het¹C₁₋₄alkyl and Het²C₁₋₄alkyl;    -   wherein R_(11b) may be linked to the remainder of the molecule        via a sulfonyl group;

-   t is, each independently, zero, 1 or 2;

-   R₂ is hydrogen or C₁₋₆alkyl;

-   L is —C(═O)—, —O—C(═O)—, —NR₈—C(═O)—, —O—C₁₋₆alkanediyl-C(═O)—,    —NR₈—C₁₋₆alkanediyl-C(═O)—, —S(═O)₂—, —O—S(═O)₂—, —NR₈—S(═O)₂,    wherein either the C(═O) group or the S(═O)₂ group is attached to    the NR₂ moiety; and wherein each independently the C₁₋₆alkanediyl    moiety may be optionally substituted with hydroxy, aryl, Het¹ or    Het²;

-   R₃ is C₁₋₆alkyl, aryl, C₃₋₇cycloalkyl, C₃₋₇cycloalkylC₁₋₄alkyl, or    arylC₁₋₄alkyl;

-   R⁴ is hydrogen, C₁₋₄alkyloxycarbonyl, carboxyl, aminocarbonyl, mono-    or di(C₁₋₄alkyl)aminocarbonyl, C₃₋₇cycloalkyl, C₂₋₆alkenyl,    C₂₋₆alkynyl or C₁₋₆alkyl optionally substituted with one or more    substituents each independently selected from aryl, Het¹, Het²,    C₃₋₇cycloalkyl, C₁₋₄alkyloxycarbonyl, carboxyl, aminocarbonyl, mono-    or di(C₁₋₄alkyl)aminocarbonyl, aminosulfonyl, mono- or    di(C₁₋₄alkyl)aminosulfonyl, C₁₋₄alkylS(═O)_(t), hydroxy, cyano,    halogen or amino optionally mono- or disubstituted where the    substituents are each independently selected from C₁₋₄alkyl, aryl,    arylC₁₋₄alkyl, C₃₋₇cycloalkyl, C₃₋₇cycloalkylC₁₋₄alkyl, Het¹, Het²,    Het¹C₁₋₄alkyl and Het²C₁₋₄alkyl;

-   R_(5a) and R_(5b) are, each independently, selected from hydrogen,    C₁₋₆alkyl, C₂₋₆alkenyl, C₂₋₆alkynyl, C₃₋₇cycloalkyl, aryl, Het¹,    Het²; wherein each of the substituents selected from C₁₋₆alkyl,    C₂₋₆alkenyl, C₂₋₆alkynyl or C₃₋₇cycloalkyl is optionally substituted    on one or more carbon atoms with a substituent independently    selected from the group consisting of amino, mono- or    di(C₁₋₄alkyl)amino, hydroxy, carboxyl, oxo, mercapto, halogen,    cyanogen, nitro, C₁₋₄alkyloxy, C₁₋₄alkylcarbonyl,    C₁₋₄alkylcarbonyloxy, C₁₋₄alkyloxycarbonyl, aryl, C₃₋₇cycloalkyl,    Het¹, Het², C₁₋₄alkylcarbonyloxy, C₁₋₄alkyloxycarbonyl;-   R₆ is hydrogen or C₁₋₆alkyl optionally substituted on one ore more    carbon atoms with one or more substituents independently selected    from the group consisting of amino, mono- or di(C₁₋₄alkyl)amino,    hydroxy, mercapto, oxo, cyanogen, nitro, halogen, carboxyl    C₁₋₄alkyloxy, C₁₋₄alkylcarbonyl, C₁₋₄alkylcarbonyloxy,    C₁₋₄alkyloxycarbonyl, C₃₋₇cycloalkyl, aryl, Het¹, Het²; wherein each    C₁₋₄alkyl may optionally be substituted by amino, mono- or    di(C₁₋₄alkyl)amino, hydroxy, mercapto, oxo, cyanogen, nitro,    halogen, carboxyl.

A special interest goes to the free base, salt or N-oxide form of thecompounds of formula (I), and their stereoisomeric forms.

A mutant of the HIV protease enzyme is defined as an HIV protease enzymewhich has at least one mutation in its amino acid sequence relative tothe amino acid sequence of the wild-type HIV protease. For purposes ofdenoting the mutants throughout the text, the HXB2 wild type reference(HIV IIIB LAI wild type), of which the sequence can be found at NIH'sGenBank, is used.

The standard of “sensitivity” or alternatively “resistance” of a HIVprotease enzyme to a drug is set by the commercially available HIVprotease inhibitors. As explained hereinabove, existing commercial HIVprotease inhibitors may loose effectivity over time against a populationof HIV virus in a patient. The reason being that under pressure of thepresence of a particular HIV protease inhibitor, the existing populationof HIV virus, usually mainly wild type HIV protease enzyme, mutates intodifferent mutants which a far less sensitive to that same HIV proteaseinhibitor. If this phenomenon occurs, one talks about resistant mutants.If those mutants are not only resistant to that one particular HIVprotease inhibitor, but also to multiple other commercially availableHIV protease inhibitors, one talks about multi-drug resistant HIVprotease. One way of expressing the resistance of a mutant to aparticular HIV protease inhibitor is making the ratio between the EC₅₀of said HIV protease inhibitor against mutant HIV protease over EC₅₀ ofsaid HIV protease inhibitor against wild type HIV protease. Said ratiois also called fold resistance (FR).

Many of the mutants occurring in the clinic have a fold resistance of100 or more against the commercially available HIV protease inhibitors,like saquinavir, indinavir, ritonavir and nelfinavir. Clinicallyrelevant mutants of the HIV protease enzyme can be characterized by amutation at codon position 10, 71 and/or 84. Examples of such clinicalrelevant mutant HIV proteases are listed in Table 2.

The compounds of the present invention show a fold resistance rangingbetween 0.01 and 100 against at least one and in several cases a broadrange of clinically relevant mutant HIV proteases. A particular group ofcompounds of formula (I) are those compounds of formula (I) showing afold resistance against at least one mutant HIV protease ranging between0.1 and 100, suitably ranging between 0.1 and 50, and more suitablyranging between 0.1 and 30. Of particular interest are the compounds offormula (I) showing a fold resistance against at least one mutant HIVprotease ranging between 0.1 and 20, and even more interesting are thosecompounds of formula (I) showing a fold resistance against at least onemutant HIV protease ranging between 0.1 and 10.

Thus, the present invention relates to the use of a compound of formula(I) in the manufacture of a medicament useful for inhibiting replicationof a HIV virus having a mutant HIV protease, in particular a multi-drugresistant mutant HIV protease. It also relates to the use of a compoundof formula (I) in the manufacture of a medicament useful for treating orcombating a disease associated with HIV viral infection wherein theprotease of the HIV virus is mutant, in particular a multi-drugresistant mutant HIV protease.

In other words, the present invention relates to a method of inhibitinga mutant HIV protease, in particular a multi-drug resistant mutant HIVprotease, in a mammal infected with said mutant HIV protease, saidmethod comprising contacting said mutant HIV protease in said mammalwith an effective amount of a compound of formula (I). The presentinvention also relates to a method of inhibiting replication of a HIVvirus, which has a mutant HIV protease, in particular a multi-drugresistant mutant HIV protease, in a mammal, said method comprisingcontacting said HIV virus, which has a mutant HIV protease, in saidmammal with an effective amount of a compound of formula (I). Thepresent invention further relates to a method of treating or combating amammalian disease associated with HIV viral infection wherein theprotease of the HIV virus is mutant, in particular a multi-drugresistant mutant HIV protease, said method comprising contacting saidHIV virus wherein the protease of the HIV virus is mutant infecting saidmammal with an effective amount of a compound of formula (I).

Of particular interest is that the compounds of the present inventioncan be used in the manufacture of a medicament for the treatment ofindividuals infected with mutant HIV protease bearing a mutation atleast at one of the amino acid positions 10, 71 or 84 or at least acombination of two of these positions or at least a combination of allthree.

A basic nitrogen occurring in the present compounds can be quaternizedwith any agent known to those of ordinary skill in the art including,for instance, lower alkyl halides, dialkyl sulfates, long chain halidesand aralkyl halides.

Whenever the term “substituted” is used in defining the compounds offormula (I), it is meant to indicate that one or more hydrogens on theatom indicated in the expression using “substituted” is replaced with aselection from the indicated group, provided that the indicated atom'snormal valency is not exceeded, and that the substitution results in achemically stable compound, i.e. a compound that is sufficiently robustto survive isolation to a useful degree of purity from a reactionmixture, and formulation into a therapeutic agent.

As used herein, the term “halo” or “halogen” as a group or part of agroup is generic for fluoro, chloro, bromo or iodo.

The term “C₁₋₄alkyl” as a group or part of a group defines straight andbranched chained saturated hydrocarbon radicals having from 1 to 4carbon atoms, such as, for example, methyl, ethyl, propyl, butyl and2-methyl-propyl and the like.

The term “C₁₋₆alkyl” as a group or part of a group defines straight andbranched chained saturated hydrocarbon radicals having from 1 to 6carbon atoms such as the groups defined for C₁₋₄alkyl and pentyl, hexyl,2-methylbutyl, 3-methylpentyl and the like.

The term “C₁₋₆alkanediyl” as a group or part of a group defines bivalentstraight and branched chained saturated hydrocarbon radicals having from1 to 6 carbon atoms such as, for example, methylene, ethan-1,2-diyl,propan-1,3-diyl, propan-1,2-diyl, butan-1,4-diyl, pentan-1,5-diyl,hexan-1,6-diyl, 2-methylbutan-1,4-diyl, 3-methylpentan-1,5-diyl and thelike.

The term “C₂₋₆alkenyl” as a group or part of a group defines straightand branched chained hydrocarbon radicals having from 2 to 6 carbonatoms containing at least one double bond such as, for example, ethenyl,propenyl, butenyl, pentenyl, hexenyl and the like.

The term “C₂₋₆alkynyl” as a group or part of a group defines straightand branched chained hydrocarbon radicals having from 2 to 6 carbonatoms containing at least one triple bond such as, for example, ethynyl,propynyl, butynyl, pentynyl, hexynyl and the like.

The term “C₃₋₇cycloalkyl” as a group or part of a group is generic tocyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl or cycloheptyl.

The term “aryl” as a group or part of a group is meant to include phenyland naphtyl which both may be optionally substituted with one or moresubstituents independently selected from C₁₋₆alkyl, optionally mono- ordisubstituted aminoC₁₋₆alkyl, C₁₋₆alkyloxy, halogen, hydroxy, optionallymono- or disubstituted amino, nitro, cyano, haloC₁₋₆alkyl,hydroxyC₁₋₆alkyl, carboxyl, C₁₋₆alkoxycarbonyl,C₁₋₆alkylcarbonyloxyC₆alkyl, C₁₋₆alkyloxycarbonylC₁₋₆alkyl,C₃₋₇cycloalkyl, Het¹, Het², optionally mono- or disubstitutedaminocarbonyl, methylthio, methylsulfonyl, and phenyl optionallysubstituted with one or more substituents each independently selectedfrom C₁₋₆alkyl, optionally mono- or disubstituted aminoC₁₋₆alkyl,C₁₋₆alkyloxy, halogen, hydroxy, optionally mono- or disubstituted amino,nitro, cyano, haloC₁₋₆alkyl, carboxyl, C₁₋₆alkoxycarbonyl,C₃₋₇cycloalkyl, Het¹, optionally mono- or disubstituted aminocarbonyl,methylthio and methylsulfonyl; wherein the optional substituents on anyamino function are independently selected from C₁₋₆alkyl,C₁₋₆alkyloxy-A-, Het¹-A-, Het¹C₁₋₆alkyl, Het¹C₁₋₆alkyl-A-, Het¹oxy-A-,Het¹oxyC₁₋₄akyl-A-, phenyl-A-, phenyl-oxy-A-, phenyloxyC₁₋₄alkyl-A-,phenylC₁₋₆alkyl-A-, C₁₋₆alkyloxycarbonylamino-A-, amino-A-,aminoC₁₋₆alkyl and aminoC₁₋₆alkyl-A- wherein each of the amino groupsmay optionally be mono- or where possible di-substituted with C₁₋₄alkyland wherein A is defined as C₁₋₆alkanediyl, —C(═O)—, —C(═S)—, —S(═O)₂—,C₁₋₆alkanediyl-C(═O)—, C₁₋₆alkanediyl-C(═S)— or C₁₋₆alkanediyl-S(═O)₂—;wherein the point of attachment of A to the nitrogen atom is theC₁₋₆alkanediyl group in those moieties containing said group.

The term “haloC₁₋₆alkyl” as a group or part of a group is defined asC₁₋₆alkyl substituted with one or more halogen atoms, preferably, chloroor fluoro atoms, more preferably fluoro atoms. Preferred haloC₁₋₆alkylgroups include for instance trifluoromethyl and difluoromethyl.

The term “hydroxyC₁₋₆alkyl” as a group or part of a group is defined asC₁₋₆alkyl substituted with one or more hydroxy moieties.

The term “Het¹” as a group or part of a group is defined as a saturatedor partially unsaturated monocyclic, bicyclic or tricyclic heterocyclehaving 3 to 14 ring members, preferably 5 to 10 ring members and morepreferably 5 to 8 ring members, which contains one or more heteroatomring members, each independently selected from nitrogen, oxygen andsulfur and which is optionally substituted on one or more carbon atomsby C₁₋₆alkyl, optionally mono- or disubstituted aminoC₁₋₆alkyl,C₁₋₆alkyloxy, halogen, hydroxy, oxo, optionally mono- or disubstitutedamino, nitro, cyano, haloC₁₋₆alkyl, hydroxyC₁₋₆alkyl, carboxyl,C₁₋₆alkoxycarbonyl, C₁₋₆alkylcarbonyloxyC₁₋₆alkyl,C₁₋₆alkyloxycarbonylC₁₋₆alkyl, C₃₋₇cycloalkyl, optionally mono- ordisubstituted aminocarbonyl, methylthio, methylsulfonyl, aryl and asaturated or partially unsaturated monocyclic, bicyclic or tricyclicheterocycle having 3 to 14 ring members which contains one or moreheteroatom ring members, each independently selected from nitrogen,oxygen or sulfur, and wherein the optional substituents on any aminofunction are independently selected from C₁₋₆alkyl, C₁₋₆alkyloxy-A-,Het²-A-, Het²C₁₋₆alkyl, Het²C₁₋₆alkyl-A-, Het² oxy-A-,Het²oxyC₁₋₄akyl-A-, aryl-A-, aryloxy-A-, aryloxyC₁₋₄alkyl-A-,arylC₁₋₆alkyl-A-, C₁₋₆alkyloxycarbonylamino-A-, amino-A-, aminoC₁₋₆alkyland aminoC₁₋₆alkyl-A- wherein each of the amino groups may optionally bemono- or where possible di-substituted with C₁₋₄alkyl and wherein A isas defined above.

The term “Het²” as a group or part of a group is defined as an aromaticmonocyclic, bicyclic or tricyclic heterocycle having 3 to 14 ringmembers, preferably 5 to 10 ring members and more preferably 5 to 6 ringmembers, which contains one or more heteroatom ring members eachindependently selected from nitrogen, oxygen or sulfur and which isoptionally substituted on one or more carbon atoms by C₁₋₆alkyl,optionally mono- or disubstituted aminoC₁₋₆alkyl, C₁₋₆alkyloxy, halogen,hydroxy, optionally mono- or disubstituted amino, nitro, cyano,haloC₁₋₆alkyl, hydroxyC₁₋₆alkyl, carboxyl, C₁₋₆alkoxycarbonylyl,C₁₋₆alkylcarbonyloxyC₁₋₆alkyl, C₁₋₆alkyloxycarbonylC₁₋₆alkyl,C₃₋₇cycloalkyl, optionally mono- or disubstituted aminocarbonyl,methylthio, methylsulfonyl, aryl, Het¹ and an aromatic monocyclic,bicyclic or tricyclic heterocycle having 3 to 14 ring members; whereinthe optional substituents on any amino function are independentlyselected from C₁₋₆alkyl, C₁₋₆alkyloxy-A-, Het¹-A-, Het¹C₁₋₆alkyl,Het¹C₁₋₆alkyl-A-, Het¹oxy-A-, Het¹oxyC₁₋₄akyl-A-, aryl-A-, aryloxy-A-,aryloxyC₁₋₄alkyl-A-, arylC₁₋₆alkyl-A-, C₁₋₆alkyloxycarbonylamino-A-,amino-A-, aminoC₁₋₆alkyl and aminoC₁₋₆alkyl-A- wherein each of the aminogroups may optionally be mono- or where possible di-substituted withC₁₋₄alkyl and wherein A is as defined above.

As used herein, the term (═O) forms a carbonyl moiety with the carbonatom to which it is attached. The term (═O) forms a sulfoxide with thesulfur atom to which it is attached. The term (═O)₂ forms a sulfonylwith the sulfur atom to which it is attached.

As used herein, the term (═S) forms a thiocarbonyl moiety with thecarbon atom to which it is attached.

As used herein before, the term “one or more” covers the possibility ofall the available C-atoms, where appropriate, to be substituted,preferably, one, two or three.

When any variable (e.g. halogen or C₁₋₄alkyl) occurs more than one timein any constituent, each definition is independent.

The term “prodrug” as used throughout this text means thepharmacologically acceptable derivatives such as esters, amides andphosphates, such that the resulting in vivo biotransformation product ofthe derivative is the active drug as defined in the compounds of formula(I). The reference by Goodman and Gilman (The Pharmacological Basis ofTherapeutics, 8^(th) ed, McGraw-Hill, Int. Ed. 1992, “Biotransformationof Drugs”, p 13–15) describing prodrugs generally is herebyincorporated. Prodrugs of a compound of the present invention areprepared by modifying functional groups present in the compound in sucha way that the modifications are cleaved, either in routine manipulationor in vivo, to the parent compound. Prodrugs include compounds of thepresent invention wherein a hydroxy group, for instance the hydroxygroup on the asymmetric carbon atom, or an amino group is bonded to anygroup that, when the prodrug is administered to a patient, cleaves toform a free hydroxyl or free amino, respectively.

Typical examples of prodrugs are described for instance in WO 99/33795,WO 99/33815, WO 99/33793 and WO 99/33792 all incorporated herein byreference.

Prodrugs are characterized by excellent aqueous solubility, increasedbioavailability and are readily metabolized into the active inhibitorsin vivo.

For therapeutic use, the salts of the compounds of formula (I) are thosewherein the counterion is pharmaceutically or physiologicallyacceptable. However, salts having a pharmaceutically unacceptablecounterion may also find use, for example, in the preparation orpurification of a pharmaceutically acceptable compound of formula (I).All salts, whether pharmaceutically acceptable or not are includedwithin the ambit of the present invention.

The pharmaceutically acceptable or physiologically tolerable additionsalt forms which the compounds of the present invention are able to formcan conveniently be prepared using the appropriate acids, such as, forexample, inorganic acids such as hydrohalic acids, e.g. hydrochloric orhydrobromic acid; sulfuric; hemisulphuric, nitric; phosphoric and thelike acids; or organic acids such as, for example, acetic, aspartic,dodecylsulphuric, heptanoic, hexanoic, nicotinic, propanoic,hydroxyacetic, lactic, pyruvic, oxalic, malonic, succinic, maleic,fumaric, malic, tartaric, citric, methane-sulfonic, ethanesulfonic,benzenesulfonic, p-toluenesulfonic, cyclamic, salicylic,p-aminosalicylic, pamoic and the like acids.

Conversely said acid addition salt forms can be converted by treatmentwith an appropriate base into the free base form.

The compounds of formula (I) containing an acidic proton may also beconverted into their non-toxic metal or amine addition salt form bytreatment with appropriate organic and inorganic bases. Appropriate basesalt forms comprise, for example, the ammonium salts, the alkali andearth alkaline metal salts, e.g. the lithium, sodium, potassium,magnesium, calcium salts and the like, salts with organic bases, e.g.the benzathine, N-methyl, -D-glucamine, hydrabamine salts, and saltswith amino acids such as, for example, arginine, lysine and the like.

Conversely said base addition salt forms can be converted by treatmentwith an appropriate acid into the free acid form.

The term “salts” also comprises the hydrates and the solvent additionforms which the compounds of the present invention are able to form.Examples of such forms are e.g. hydrates, alcoholates and the like.

The N-oxide forms of the present compounds are meant to comprise thecompounds of formula (I) wherein one or several nitrogen atoms areoxidized to the so-called N-oxide.

The present compounds may also exist in their tautomeric forms. Suchforms, although not explicitly indicated in the above formula areintended to be included within the scope of the present invention.

The term stereochemically isomeric forms of compounds of the presentinvention, as used hereinbefore, defines all possible compounds made upof the same atoms bonded by the same sequence of bonds but havingdifferent three-dimensional structures which are not interchangeable,which the compounds of the present invention may possess. Unlessotherwise mentioned or indicated, the chemical designation of a compoundencompasses the mixture of all possible stereochemically isomeric formswhich said compound may possess. Said mixture may contain alldiastereomers and/or enantiomers of the basic molecular structure ofsaid compound. All stereochemically isomeric forms of the compounds ofthe present invention both in pure form or in admixture with each otherare intended to be embraced within the scope of the present invention.

Pure stereoisomeric forms of the compounds and intermediates asmentioned herein are defined as isomers substantially free of otherenantiomeric or diastereomeric forms of the same basic molecularstructure of said compounds or intermediates. In particular, the term‘stereoisomerically pure’ concerns compounds or intermediates having astereoisomeric excess of at least 80% (i.e. minimum 90% of one isomerand maximum 10% of the other possible isomers) up to a stereoisomericexcess of 100% (i.e. 100% of one isomer and none of the other), more inparticular, compounds or intermediates having a stereoisomeric excess of90% up to 100%, even more in particular having a stereoisomeric excessof 94% up to 100% and most in particular having a stereoisomeric excessof 97% up to 100%. The terms ‘enantiomerically pure’ and‘diastereomerically pure’ should be understood in a similar way, butthen having regard to the enantiomeric excess, respectively thediastereomeric excess of the mixture in question.

Pure stereoisomeric forms of the compounds and intermediates of thisinvention may be obtained by the application of art-known procedures.For instance, enantiomers may be separated from each other by theselective crystallization of their diastereomeric salts with opticallyactive acids or bases. Examples thereof are tartaric acid,dibenzoyl-tartaric acid, ditoluoyltartaric acid and camphosulfonic acid.Alternatively, enantiomers may be separated by chromatographictechniques using chiral stationary phases. Said pure stereochemicallyisomeric forms may also be derived from the corresponding purestereochemically isomeric forms of the appropriate starting materials,provided that the reaction occurs stereospecifically. Preferably, if aspecific stereoisomer is desired, said compound will be synthesized bystereospecific methods of preparation. These methods will advantageouslyemploy enantiomerically pure starting materials.

The diastereomeric racemates of formula (I) can be obtained separatelyby conventional methods. Appropriate physical separation methods whichmay advantageously be employed are, for example, selectivecrystallization and chromatography, e.g. column chromatography.

It is clear to a person skilled in the art that the compounds of formula(I) contain at least two asymmetric centers and thus may exist asdifferent stereoisomeric forms. These two asymmetric centers areindicated with an asterisk (*) in the figure below.

The absolute configuration of each asymmetric center that may be presentin the compounds of formula (I) may be indicated by the stereochemicaldescriptors R and S, this R and S notation corresponding to the rulesdescribed in Pure Appl. Chem. 1976, 45, 11–30. The carbon atom bearingthe hydroxy group and marked with the asterisk (*) preferably has the Rconfiguration. The carbon atom bearing the R³ group and marked with theasterisk (*) preferably has the S configuration.

The present invention is also intended to include all isotopes of atomsoccurring on the present compounds. Isotopes include those atoms havingthe same atomic number but different mass numbers. By way of generalexample and without limitation, isotopes of hydrogen include tritium anddeuterium. Isotopes of carbon include C-13 and C-14.

Whenever used hereinafter, the term “compounds of formula (I)”, or “thepresent compounds” or similar term is meant to include the compounds ofgeneral formula (I), their N-oxides, salts, stereoisomeric forms,racemic mixtures, prodrugs, esters and metabolites, as well as theirquaternized nitrogen analogues.

A particular group of compounds are those compounds of formula (I)wherein one or more of the following restrictions apply:

-   R₁ is hydrogen, Het¹, Het², aryl, Het¹C₁₋₆alkyl, Het²C₁₋₆alkyl,    arylC₁₋₆alkyl; more in particular, R₁ is hydrogen, a saturated or    partially unsaturated monocyclic or bicyclic heterocycle having 5 to    8 ring members, which contains one or more heteroatom ring members,    each independently selected from nitrogen, oxygen or sulfur and    which is optionally substituted, phenyl optionally substituted with    one or more substituents, an aromatic monocyclic heterocycle having    5 to 6 ring members, which contains one or more heteroatom ring    members, each independently selected from nitrogen, oxygen or sulfur    and which is optionally substituted on one or more carbon atoms, or    C₁₋₆alkyl substituted with an aromatic monocyclic heterocycle having    5 to 6 ring members, which contains one or more heteroatom ring    members, each independently selected from nitrogen, oxygen or sulfur    and which is optionally substituted on one or more carbon atoms;-   R₂ is hydrogen;-   L is —C(═O)—, —O—C(═O)—, —O—C₁₋₆alkanediyl-C(═O)—, more in    particular, L is —C(═O)—, —O—C(═O)—, —O—CH₂—C(═O)—, wherein the    C(═O) group is attached to the NR₂ moiety;-   R₃ is arylC₁₋₄alkyl, in particular, arylmethyl, more in particular    phenylmethyl;-   R₄ is optionally substituted C₁₋₆alkyl, in particular C₁₋₆alkyl    optionally substituted with aryl, Het¹, Het², C₃₋₇cycloalkyl or    amino optionally mono- or disubstituted where the substituents are    each independently selected from C₁₋₄alkyl, aryl, Het¹ and Het²;-   Q is >C═C—R_(5a) wherein R_(5a) is aryl, Het¹, He²; wherein each of    said substituents is optionally substituted on one or more atoms    with a substituent independently selected from the group consisting    of amino, mono- or di(C₁₋₄alkyl)amino, hydroxy, C₁₋₆alkyloxy,    carboxyl, oxo, C₁₋₆alkyl, hydroxyC₁₋₆alkyl, C₁₋₄alkylcarbonyloxy,    C₁₋₄alkyloxycarbonyl, C₁₋₄alkylcarbonyloxyC ₁₋₄alkyl,    C₁₋₄alkyloxycarbonyl C₁₋₄alkyl, Het²; R_(5a) may also be C₁₋₆alkyl    optionally further substituted with amino, mono- or    di(C₁₋₄alkyl)amino, hydroxy, C₁₋₆alkyloxy, carbonyl, oxo, mercapto,    C₁₋₄alkylcarbonyloxy, C₁₋₄alkyloxycarbonyl;-   Q is >C═C—R_(5b) wherein R_(5b) is hydrogen; and-   R₆ is hydrogen.

A special group of compounds are those compounds of formula (I) wherein,

-   R₂ is hydrogen;-   L is —C(═O)—, —O—C(═O)—, —O—CH₂—C(═O)—, wherein the C(═O) group is    attached to the NR₂ moiety;-   R₃ is phenylmethyl; and-   R₄ is C₁₋₆alkyl; and-   Q is >C═C—R_(5a) wherein R_(5a) is Het¹, aryl, Het²; wherein each of    said substituents is optionally substituted on one or more atoms    with a substituent independently selected from the group consisting    of amino, mono- or di(C₁₋₄alkyl)amino, hydroxy, C₁₋₆alkyloxy,    aminoC₆alkyl, mono- or di(C₁₋₄alkyl)aminoC₁₋₄alkyl, carboxyl, oxo,    C₁₋₆alkyl, hydroxyC₁₋₆alkyl, mercapto, C₁₋₄alkylcarbonyloxy,    C₁₋₄alkyloxycarbonyl, C₁₋₄alkylcarbonyloxyC₁₋₄alkyl,    C₁₋₄alkyloxycarbonylC₁₋₄alkyl, C₃₋₇cycloalkyl, aryl, Het¹, Het².

Another special group of compounds are those compounds of formula (I)wherein,

-   R₂ is hydrogen;-   L is —C(═O)—, —O—C(═O)—, —O—CH₂—C(═O)—, wherein the C(═O) group is    attached to the NR₂ moiety;-   R₃ is phenylmethyl;-   R₄ is C₁₋₆alkyl; and-   Q is >C═C—R_(5a) wherein R_(5a) is aryl, optionally substituted on    one or more atoms with a substituent independently selected from the    group consisting of amino, mono- or di(C₁₋₄alkyl)amino, hydroxy,    C₁₋₆alkyloxy, aminoC₁₋₆alkyl, mono- or di(C₁₋₄alkyl)aminoC₁₋₄alkyl,    carboxyl, oxo, C₁₋₆alkyl, hydroxyC₁₋₆alkyl, mercapto,    C₁₋₄alkylcarbonyloxy, C₁₋₄alkyloxycarbonyl, C₁₋₄alkylcarbonyloxy    C₁₋₄alkyl, C₁₋₄alkyloxycarbonyl C₁₋₄alkyl, C₃₋₇cycloalkyl, aryl,    Het¹, Het².

Yet another special group of compounds are those compounds of formula(I) wherein,

-   R₂ is hydrogen;-   L is —C(═O)—, —O—C(═O)—, —O—CH₂—C(═O)—, wherein the C(═O) group is    attached to the NR₂ moiety;-   R₃ is phenylmethyl; and-   R₄ is C₁₋₆alkyl; and-   Q is >C═C—R_(5b) wherein R_(5b) is hydrogen.

Another interesting group of compounds are those of formula (I) wherein,

-   R₂ is hydrogen;-   L is —C(═O)—, —O—C(═O)—, —O—CH₂—C(═O)—, wherein the C(═O) group is    attached to the NR₂ moiety;-   R₃ is phenylmethyl;-   R₄ is C₁₋₆alkyl; and-   Q is >C═C—R_(5a) wherein R_(5a) is Het² optionally substituted on    one or more atoms with a substituent independently selected from the    group consisting of amino, mono- or di(C₁₋₄alkyl)amino, hydroxy,    C₁₋₆alkyloxy, aminoC₁₋₆alkyl, mono- or di(C₄alkyl)aminoC₁₋₆alkyl,    carboxyl, oxo, C₁₋₆alkyl, hydroxyC₁₋₆alkyl, mercapto,    C₁₋₄alkylcarbonyloxy, C₁₋₄alkyloxycarbonyl, C₁₋₄alkylcarbonyloxy    C₁₋₄alkyl, C₁₋₄alkyloxycarbonyl C₁₋₄alkyl.

Another particular group are those compounds of formula (I), wherein,

-   R₂ is hydrogen;-   L is —C(═O)—, —O—C(═O)—, —O—CH₂—C(═O)—, wherein the C(═O) group is    attached to the NR₂ moiety;-   R₃ is phenylmethyl;-   R₄ is C₁₋₆alkyl; and-   Q is >C═C—R_(5a) wherein R_(5a) is alkyl optionally substituted on    one or more atoms with a substituent independently selected from the    group consisting of amino, mono- or di(C₁₋₄alkyl)amino, hydroxy,    C₁₋₆alkyloxy, carboxyl, oxo, C₁₋₄alkylcarbonyloxy,    C₁₋₄alkyloxycarbonyl, C₃₋₇cycloalkyl, aryl, Het¹, Het².

Another interesting group of compounds are those compounds of formula(I) wherein L is —O—C₁₋₆alkanediyl-C(═O)—.

Another group of compounds are those compounds of formula (I) wherein Qis >C═C—R_(5a) wherein R_(5a) is C₁₋₆alkyl, aryl, or Het²; eachoptionally substituted on one or more atoms with a substituentindependently selected from the group consisting of amino, mono- ordi(C₁₋₄alkyl)amino, hydroxy, C₁₋₄alkyloxy, carboxyl, oxo, sulfhydryl,C₁₋₄alkylcarbonyloxy, C₁₋₄alkyloxycarbonyl, C₃₋₇cycloalkyl, aryl, Het¹and Het².

Yet another group of compounds are those compounds of formula (I) or anysubgroup thereof wherein Q is >C—R_(5b) wherein R_(5b) is hydrogen.

A special group of compounds are those compounds of formula (I) whereinR₁-L is Het¹-O—C(═O), Het²-C₁₋₆alkanediyl-O—C(═O),aryl-O—C₁₋₆alkanediyl-C(═O) or aryl-C(═O).

Of particular interest are those compounds of formula (I) wherein R₁ ishydrogen, C₁₋₆alkyl, C₂₋₆alkenyl, arylC₁₋₆alkyl, C₃₋₇cycloalkyl,C₃₋₇cycloalkylC₁₋₆alkyl, aryl, Het¹, Het¹C₁₋₆alkyl, Het², Het²C₁₋₆alkyl,in particular, R₁ is hydrogen, C₁₋₆alkyl, C₂₋₆alkenyl, arylC₁₋₆alkyl,C₃₋₇cycloalkyl, C₃₋₇cycloalkylC₁₋₆alkyl, aryl, Het², Het²C₁₋₆alkyl.

An interesting group of compounds are those compounds of formula (I)wherein R₁ is hydrogen, C₁₋₆alkyl, C₂₋₆alkenyl, arylC₁₋₆alkyl,C₃₋₇cycloalkyl, C₃₋₇cycloalkyl-C₁₋₆alkyl, aryl, Het¹, Het¹C₁₋₆alkyl,Het², Het²C₁₋₆alkyl; wherein Het¹ has 5 or 6 ring members, whichcontains one or more heteroatom ring members selected from nitrogen,oxygen or sulfur and which is optionally substituted on one or more ringmembers.

A preferred group of compounds are those compounds where the sulfonamidegroup is attached to the oxindole group in the 6-position.

A suitable group of compounds are those compounds of formula (I) whereinR₁ is aryl or arylC₁₋₆alkyl; in particular the aryl moiety of the R₁definition is further substituted on one or more ring members, whereineach substituent is independently selected from C₁₋₄alkyl, hydroxy,halogen, optionally mono- or di(C₁₋₄alkyl)amino, optionally mono- ordi(C₁₋₄alkyl)aminoC₄alkyl, nitro and cyanogen; preferably thesubstituent is selected from methyl, ethyl, chlorine, iodine, bromine,hydroxy and cyanogens, in particular the aryl moiety contains 6 to 12ring members, more in particular the aryl moiety in the definition of R₁contains 6 ring members.

A suitable group of compounds are those compounds of formula (I) whereinR₁ is Het² or Het²C₁₋₆alkyl, wherein the Het² in the definition of R₁contains one or more heteroatoms each independently selected fromnitrogen, oxygen and sulfur; in particular the Het² moiety of the R₁definition is further substituted on one or more ring members, whereineach substituent is independently selected from C₁₋₄alkyl, hydroxy,halogen, optionally mono- or disubstituted amino and cyanogen;preferably the substituent is selected from methyl, ethyl, chlorine,iodine, bromine, hydroxy, amino and cyanogen.

Another group of compounds are those of formula (I) wherein R₁ is Het²or Het²C₁₋₆alkyl, L is —C(═O)—, —O—C(═O)—, —O—C₁₋₆alkanediyl-C(═O)—; inparticular the Het² moiety in the definition of R₁ is an aromaticheterocycle having 5 or 6 ring members, which contain one or moreheteroatom ring members each independently selected from nitrogen,oxygen or sulfur, more in particular the Het² moiety is an aromaticheterocycle having 5 or 6 ring members, which contain two or moreheteroatom ring members each independently selected from nitrogen,oxygen or sulfur.

A suitable group of compounds are those compounds of formula (I) whereinR₁ is Het¹ or Het¹C₁₋₆alkyl, wherein Het¹ in the definition of R₁contains one or more heteroatoms each independently selected fromnitrogen, oxygen and sulfur; in particular the Het¹ moiety of thedefinition of R₁ is further substituted on one or more ring members,wherein each substituent is independently selected from C₁₋₄alkyl,hydroxy, halogen, optionally mono- or disubstituted amino and cyanogen;preferably the substituent is selected from methyl, ethyl, chlorine,iodine, bromine, hydroxy, amino and cyanogen.

A suitable group of compounds are those compounds of formula (I) whereinR₁ is Het¹C₁₋₆alkyl, Het¹, wherein said Het¹ in the definition of R₁ ismonocyclic having 5 or 6 ring members, wherein the Het¹ contains one ormore heteroatoms each independently selected from nitrogen, oxygen andsulfur; in particular the Het¹ moiety of the R₁ definition is furthersubstituted on one or more carbon atoms, wherein each substituent isindependently selected from C₁₋₄alkyl, hydroxy, halogen, optionallymono- or disubstituted amino and cyanogen; preferably the substituent isselected from methyl, ethyl, chlorine, iodine, bromine, hydroxy, aminoand cyanogen.

A suitable group of compounds are those compounds of formula (I) whereinR₁ is Het¹, wherein said Het¹ is bicyclic having 7 to 10 ring members,wherein the Het¹ contains one or more heteroatoms each independentlyselected from nitrogen, oxygen and sulfur; in particular the Het¹ moietyof the R₁ definition is further substituted on one or more carbon atoms,wherein each substituent is independently selected from C₁₋₄alkyl,hydroxy, halogen, optionally mono- or disubstituted amino and cyanogen;preferably the substituent is selected from methyl, ethyl, chlorine,iodine, bromine, hydroxy, amino and cyanogens, in particular the Het¹moiety contains 2 or more heteroatoms selected from nitrogen, sulfur andoxygen; in one aspect R₁ is a bicyclic Het¹ containing containing at oneoxygen heteroatom, L is selected from —O—(C═O)— and Q is >C═C—R_(5a)with R_(5a) and R₆ are hydrogen.

A suitable group of compounds are those compounds of formula (I) whereinR₁ is Het¹, wherein said Het¹ is a satured bicyclic group having 5 to 10ring members, wherein the Het¹ contains one or more heteroatoms eachindependently selected from nitrogen, oxygen and sulfur; in particularthe Het¹ moiety of the R₁ definition is further substituted on one ormore carbon atoms, wherein each substituent is independently selectedfrom C₁₋₄alkyl, hydroxy, halogen, optionally mono- or disubstitutedamino and cyanogen; preferably the substituent is selected from methyl,ethyl, chlorine, iodine, bromine, hydroxy, amino and cyanogens; inparticular Het¹ contains 5 to 8 ring members; in particular the Het¹moiety has 6 to 8 ring members wherein Het¹ contains 2 or moreheteroatoms selected from nitrogen, sulfur and oxygen.

A suitable group of compounds are those compounds of formula (I) whereinR₁-L- is bis-tetrahydrofurane-O—C(═O)—.

An interesting group of compounds are those compounds of formula (I)wherein R₁ is G or G-C₁₋₆alkyl, wherein G is selected from thiazolyl,imidazolyl, oxazolyl, oxadiazolyl, dioxazolyl, pyrazolyl, pyrazinyl,imidazolinonyl, quinolinyl, isoquinolinyl, indolyl, pyridazinyl,pyridinyl, pyrrolyl, pyranyl, pyrimidinyl, furanyl, triazolyl,tetrazolyl, benzofuranyl, benzoxazolyl, isoxazolyl, isothiazolyl,thiadiazolyl, thiophenyl, tetrahydrofurofuranyl,tetrahydropyranofuranyl, benzothiophenyl, carbazoyl, imidazolonyl,oxazolonyl, indolizinyl, triazinyl, quinoxalinyl, piperidinyl,piperazinyl, morpholinyl, thiamorpholinyl, pyrazinyl, thienyl,tetrahydroquinolinyl, tetrahydroisoquinolinyl, β-carbolinyl, dioxanyl,dithianyl, oxolanyl, dioxolanyl, tetrahydrothiophenyl,tetrahydropyranyl, tetrahydropyranyl; wherein G is optionallybenzofused; wherein G is optionally further substituted on one or morering members; preferably G is selected from thiazolyl, imidazolyl,oxazolyl, oxadiazolyl, pyrazolyl, pyridinyl, optionally substituted onone or more ring members.

Interesting compounds are those compounds of formula (I) wherein R₁ ishexahydrofuro[2,3-b]furanyl or oxazolyl.

Other interesting compounds are those compounds of formula (I) or thosecompounds belonging to any subgroup thereof wherein R₁ ishexahydrofuro[2,3-b]furanyl, tetrahydrofuranyl, oxazolyl, thiazolyl, andL is a direct bond.

Yet other interesting compounds are those compounds of formula (I) orthose compounds belonging to any subgroup thereof wherein R₁ ishexahydrofuro[2,3-b]furanyl, oxazolyl, thiazolyl, pyridinyl, or phenyloptionally substituted with one or more substituents independentlyselected from C₁₋₆alkyl, hydroxy, amino, halogen, aminoC₁₋₄alkyl andmono-or di(C₁₋₄alkyl)amino; and L is —O—.

Still other interesting compounds are those compounds of formula (I) orthose compounds belonging to any subgroup thereof wherein R₁ ishexahydrofuro[2,3-b]furanyl, tetrahydrofuranyl, oxazolyl, or phenylsubstituted with one or more substituents independently selected fromC₁₋₆alkyl, hydroxy, amino, halogen, aminoC₁₋₄alkyl and mono-ordi(C₁₋₄alkyl)amino; and L is C₁₋₆alkanediyl-O— wherein the —O— isattached to the nitrogen of the amide.

Also interesting compounds are those compounds of formula (I) or thosecompounds belonging to any subgroup thereof wherein R₁ ishexahydrofuro[2,3-b]furanyl, tetrahydrofuranyl, oxazolyl, thiazolyl,pyridinyl, or phenyl optionally substituted with one or moresubstituents independently selected from hydroxy, amino, halogen,aminoC₁₋₄alkyl and mono-or di(C₁₋₄alkyl)amino; and L is—O—C₁₋₆alkanediyl wherein —O— is attached to the R₁ group.

Compounds of particular interest are those compounds of formula (I) orthose compounds belonging to any subgroup thereof wherein -L-R¹ is—O-(hexahydrofuro[2,3-b]furanyl), —O-tetrahydrofuranyl,—O-methyl-(optionally substituted phenyl), —O-methyl-pyridinyl,—O-methyl-thiazolyl, —O-methyl-oxazolyl, -methyl-O-(optionallysubstituted phenyl) or optionally substituted phenyl. Preferably, theoptional substituents on the phenyl group are methyl, amino, hydroxy,halogen, aminomethyl,

Compounds of special interest are those compounds of formula (I) orthose compounds belonging to any subgroup thereof wherein R₁ ishexahydrofuro[2,3-b]furanyl, tetrahydrofuranyl, oxazolyl, thiazolyl,pyridinyl, or phenyl optionally substituted with one or moresubstituents independently selected from C₁₋₆alkyl, hydroxy, amino,chloro, bromo, aminoC₁₋₄alkyl and mono-or di(C₁₋₄alkyl)amino.

Another special subgroup of the compounds of formula (I) or of thecompounds belonging to any subgroup thereof are those compounds wherein-L-R¹ is —O—(hexahydrofuro[2,3-b]furanyl), —O-tetrahydrofuranyl,—O-methyl-thiazolyl, —O—methyl-oxazolyl, -methyl-O-(2,6-dimethylphenyl),-methyl-O-(4-aminomethyl-2,6-dimethylphenyl),-methyl-O-(4-amino-2,6-dimethylphenyl), 3-hydroxy-2-methyl-phenyl or3-amino-2-methyl-phenyl; and Q is >C═C—R_(5a) with R_(5a) is methyl orhydrogen and R⁶ is hydrogen.

A suitable group of compounds are those compounds of formula (I) as asalt, wherein the salt is selected from trifluoroacetate, fumarate,chloroacetate and methanesulfonate.

An interesting group of compounds are those compounds of formula (I)having a fold resistance, determined according to the methods hereindescribed, in the range of 0.01 to 100 against HIV species having atleast one mutation in the HIV protease as compared to the wild typesequence (e.g. M38432, K03455, gi 327742) at a position selected from10, 71 and 84; in particular at least two mutations selected from 10, 71and 84 are present in the HIV protease; in particular the compounds havea fold resistance in the range of 0.1 to 100, more in particular in therange 0.1 to 50, suitably in the range 0.1 to 30. Of particular interestare the compounds of formula (I) showing a fold resistance against atleast one mutant HIV protease ranging between 0.1 and 20, and even moreinteresting are those compounds of formula (I) showing a fold resistanceagainst at least one mutant HIV protease ranging between 0.1 and 10.Interesting compounds have in addition an IC₅₀ of at least 100 nMvis-à-vis the wild type virus upon in vitro screening according to themethods described herein.

Preferred compounds are those enantiomeric forms of the compounds offormula (I) or of the compounds belonging to any subgroup thereof havinga (1S,2R)-1-benzyl-2-hydroxy-propyl configuration.

An interesting group of compounds of formula (I) are those compoundswherein R_(5b) is hydrogen.

Most preferred compounds are (1-Benzyl-2-hydroxy-3-{isobutyl-[2-(1-Benzyl-2-hydroxy-3-{isobutyl-[2- oxo-3-(1H-pyrrol-2-ylmethylene)-2,3-oxo-3-(4-pyridin-2-yl-benzylidene)-dihydro-1H-indole-5-sulfonyl]-amino}- 2,3-dihydro-1H-indole-5-sulfonyl]-propyl)-carbamic acid hexahydrofuro amino}-propyl)-carbamic acidhexahydro- [2,3-b]furan-3-yl ester furo[2,3-b]furan-3-yl ester(1-Benzyl-2-hydroxy-3-{isobutyl-[3-(1-Benzyl-2-hydroxy-3-{[3-(4-hydroxy-(5-methyl-furan-2-ylmethylene)-2-oxo-3,5-dimethyl-benzylidene)-2-oxo-2,3- 2,3-dihydro-1H-indole-5-sulfonyl]-dihydro-1H-indole-5-sulfonyl]-iso amino}-propyl)-carbamic acid hexa-butyl-amino}-propyl)-carbamic acid hydro-furo[2,3-b]furan-3-yl esterhexahydro-furo[2,3-b]furan-3-yl ester(1-Benzyl-2-hydroxy-3-{isobutyl-[3- (1-Benzyl-3-{[3-(4-dimethylamino-(5-methyl-thiophen-2-ylmethylene)-2-benzylidene)-2-oxo-2,3-dihydro-1H-indole-oxo-2,3-dihydro-1H-indole-5-sulfonyl]-5-sulfonyl]-isobutyl-amino}-2-hydroxy- amino}-propyl)-carbamic acidhexa- propyl)-carbamic acid hexahydro-furo hydro-furo[2,3-b]furan-3-ylester [2,3-b]furan-3-yl ester (1-Benzyl-2-hydroxy-3-{isobutyl-[3-(1-Benzyl-2-hydroxy-3-{[3-(1H-indol- (1-methyl-1H-pyrrol-2-ylmethylene)-2-ylmethylene)-2-oxo-2,3-dihydro-1H-2-oxo-2,3-dihydro-1H-indole-5-sulfonyl]-indole-5-sulfonyl]-isobutyl-amino}- amino}-propyl)-carbamic acid hexa-propyl)-carbamic acid hexahydro-furo hydro-furo[2,3-b]furan-3-yl ester[2,3-b]furan-3-yl ester (1-Benzyl-3-{[3-(2-ethyl-butylidene)- Aceticacid 5-(5-{[3-(hexahydro-furo 2-oxo-2,3-dihydro-1H-indole-5-sulfonyl]-[2,3-b]furan-3-yloxycarbonylamino)-2- isobutyl-amino}-2-hydroxy-propyl)-hydroxy-4-phenyl-butyl]-isobutyl-sulfa- carbamic acidhexahydro-furo[2,3-b] moyl}-2-oxo-1,2-dihydro-indol-3- furan-3-yl esterylidenemethyl)-furan-2-ylmethyl ester{1-Benzyl-2-hydroxy-3-[isobutyl-(3- {1-Benzyl-3-[(3-benzylidene-2-oxo-isobutylidene-2-oxo-2,3-dihydro-1H-2,3-dihydro-1H-indole-5-sulfonyl)-iso-indole-5-sulfonyl)-amino]-propyl}-butyl-amino]-2-hydroxy-propyl}-carbamic carbamic acidhexahydro-furo[2,3-b] acid hexahydro-furo[2,3-b]furan- furan-3-yl ester3-yl ester {1-Benzyl-3-[(3-furan-2-ylmethylene-(1-Benzyl-3-{[3-(4-diethylamino-3-2-oxo-2,3-dihydro-1H-indole-5-sulfonyl)-hydroxy-benzylidene)-2-oxo-2,3-dihydro-isobutyl-amino]-2-hydroxy-propyl}-1H-indole-5-sulfonyl]-isobutyl-amino}- carbamic acidhexahydro-furo[2,3-b] 2-hydroxy-propyl)-carbamic acid hexahydro-furan-3-yl ester furo[2,3-b]furan-3-yl ester(1-Benzyl-2-hydroxy-3-{isobutyl-[3-(1-Benzyl-2-hydroxy-3-{[3-(2-hydroxy-(4-methoxy-benzylidene)-2-oxo-2,3-dihydro-benzylidene)-2-oxo-2,3-dihydro-1H- 1H-indole-5-sulfonyl]-amino}-indole-5-sulfonyl]-isobutyl-amino}- propyl)-carbamic acid hexahydro-furopropyl)-carbamic acid hexahydro-furo [2,3-b]furan-3-yl ester[2,3-b]furan-3-yl ester (1-Benzyl-2-hydroxy-3-{isobutyl-[3-(1-Benzyl-3-{isobutyl-[3-(5-methyl- (2-methoxy-benzylidene)-2-oxo-2,3-furan-2-ylmethylene)-2-oxo-2,3-dihydro-dihydro-1H-indole-5-sulfonyl]-amino}- 1H-indole-5-sulfonyl]-amino}-2-propyl)-carbamic acid hexahydro-furo phosphonooxy-propyl)-carbamic acid[2,3-b]furan-3-yl ester hexahydro-furo[2,3-b]furan-3-yl ester(1-Benzyl-2-hydroxy-3-{[3-(4-hydroxy-4-(5-{[3-(Hexahydro-furo[2,3-b]furan- 3-methoxy-benzylidene)-2-oxo-2,3-3-yloxycarbonylamino)-2-hydroxy-4-phenyl-dihydro-1H-indole-5-sulfonyl]-isobutyl-butyl]-isobutyl-sulfamoyl}-2-oxo- amino}-propyl)-carbamic acidhexahydro- 1,2-dihydro-indol-3-ylidenemethyl)-benzoicfuro[2,3-b]furan-3-yl ester acid the N-oxides and salts thereof andtheir stereoisomeric forms.

The compounds of formula (I) can generally be prepared using proceduresanalogous to those procedures described in WO 95/06030, WO 96/22287, WO96/28418, WO 96/28463, WO 96/28464, WO 96/28465 and WO 97/18205.

Particular reaction procedures to make the present compounds aredescribed below. In the preparations described below, the reactionproducts may be isolated from the medium and, if necessary, furtherpurified according to methodologies generally known in the art such as,for example, extraction, crystallization, trituration andchromatography.

Intermediates of formula (a-2) can be prepared by reacting1,3-dihydro-indol-2-one (a-1) with chlorosulphonic acid at an elevatedtemperature, suitably ranging between 50 and 60° C., and stirring theresulting intermediate.

In order to obtain nitrogen substituted 1,3-dihydro-indol-2-ones offormula (a-3), 1,3-dihydro-indol-2-one can be reacted with an activatedalkylderivative R₆X, such as an alkylhalide in a suitable aprotic polarsolvent and in the presence of a base. Intermediates of formula a-4 canthen be prepared starting from intermediates a-3 according to schemeA-1.

Preparation of b-1

This intermediate may be prepared according to the procedures outlinedin WO 97/18205.

Preparation of b-2

Intermediate b-1 was stirred in an organic solvent in the presence of acatalyst such as Pd/C or Pd/OH under an hydrogen atmosphere. Under theseconditions protecting group P₁ is removed.

Preparation of b-3.

To intermediate b-2, in an organic solvent, was added R₁-(L)-(leavinggroup) and a base. Alternatively, R₁-(L)-(leaving group) may be added inthe presence of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimidehydrochloric acid (EDC) and 1-hydroxybenzotriazole (HOBT) in an organicsolvent. The reaction mixture was stirred 6 to 24 hours at temperaturesranging from 15 to 40° C. and the solvent was evaporated.

Preparation of b-4.

An alcoholic solution of intermediate b-3; was acidified to removeprotecting group P₂. The mixture was stirred during 6 to 24 hours attemperatures ranging from 15 to 40° C., whereafter an organic solventwas added. The pH of the mixture was neutralized and subsequently washedwith brine. The organic layer was dried and concentrated to yieldintermediate b-4.

Preparation of b-5

Intermediate a-4 was added to a mixture of intermediate b-4 in anorganic solvent and in the presence of an amine. The mixture was stirredat temperatures ranging from 15 to 40° C. for 4-24 hours and washed witha alkaline solution. The organic layer was dried and the solvent wasevaporated.

Preparation of b-6

Reaction of intermediate b-5 with aldehydes (R_(5a)-C(═O)—H) results inthe generation of b-6. The reaction is suitably performed in alcohols inthe presence of an organic base at elevated temperatures ranging from50° C. to reflux temperature.

Intermediate c-2, may be prepared by adding an amine of formula H₂N—R₄to an intermediate c-1 in a suitable solvent such as isopropanol.

In scheme D, enantiomerically pure compounds of formula c-2 are onlyobtained if c-1 is enantiomerically pure. If c-1 is a mixture ofstereoisomers, than c-2 will also consist of a mixture of stereoisomers.

DETAILED DESCRIPTION OF THE SYNTHESIS

1. Scheme A-1

A mixture of 46 ml chlorosulfonic acid and 10 g of1,3-dihydro-indol-2-one (a-1) was heated to 50° C. during 12 hours.After cooling down to room temperature, the mixture was poured on iceand water and extracted with dichloromethane. The organic layer wasseparated, dried over MgSO₄ and the solvent was evaporated to yield16.33 g (94%) of intermediate a-2(2-oxo-2,3-dihydro-1H-indole-5-sulfonyl chloride).

2. Scheme A-2

In order to obtain nitrogen substituted 1,3-dihydro-indol-2-ones offormula (a-3), 1,3-dihydro-indol-2-one can be reacted with an activatedalkylderivative R₆X, such as an alkylhalide in a suitable aprotic polarsolvent solvent such as tetrahydrofuran (THF), dimethylformamide (DMF),dichloremethane (DCM) and in the presence of a base such as NaH,potassium carbonate or sodium carbonate. The mixture was stirred at roomtemperature (RT) and activated alkyls such as alkyl halide or acylhalide were added (R₆—X, wherein X is a halogen, suitably selected fromCl, I, Br; R₆ is selected from —C₁₋₆alkyl, —C(═O)—C₁₋₆alkyl,—CH₂—C(═O)O—C₁₋₆alkyl). The reaction mixture was stirred overnight atRT. Then water was added and the mixture was extracted with a suitablesolvent and dried on magnesium sulphate. Intermediate a-3 was isolatedby crystallisation or purification on silica gel. Intermediate a-4 wasobtained according to the procedure outlined in Scheme A-1

3. Scheme B

3.1 Preparation of b-1

This intermediate may be prepared according to the procedures outlinedin WO 97/18205.

3.2 Preparation of b-2

The mixture of intermediate b-1 in the presence of Pd/C in alcohols andor Pd/OH in cyclohexene or 1,3-cyclohexa-diene was stirred overnight ina hydrogen atmosphere to remove protecting group P₁. For the purpose ofthe synthesis of the compounds of the present invention, R₂ at thisstage of the synthesis, may also be a protecting group P₁. A preferredprotecting group is benzyl, more preferable P₁ and R₂ are both benzyl,thus forming a dibenzyl moiety. Suitable alcohols for said reaction aree.g. MeOH, EtOH, isopropanol. The mixture was filtered and the solventwas evaporated to yield intermediate b-2.

3.3 Preparation of b-3.

To intermediate b-2, in an organic solvent, was added R₁-(L)-(leavinggroup) and a base. This reaction is a preferred route to generatecarbamates. Alternatively, R₁-(L)-(leaving group) may be added in thepresence of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloricacid (EDC) and 1-hydroxybenzotriazole (HOBT) or an alcohol such astertbutanol in a suitable solvent such as dichloromethane. Using thealternative strategy amides may be obtained. The reaction mixture wasstirred overnight at RT and the solvent evaporated. The intermediate waspurified on silica gel.

3.4 Preparation of b-4.

A mixture of intermediate b-3, in alcohols such as methanol, ethanol orisopropanol, was acidified (e.g. by the addition of HCl) to removeprotecting group P₂. Suitable protecting groups are e.g. boc, Fmoc, Cbz.A preferred protecting group is boc. The mixture was stirred over nightat RT. Then an organic solvent was added. Suitable solvents are e.g.ethylacetate, acetonitrile, aceton, cyclohexane, chloroform, toluene.The pH of the mixture was neutralized and subsequently washed withbrine. Neutralization can suitably be done by sodium carbonate. Theorganic layer was dried over MgSO₄ and concentrated to yieldintermediate b-4.

3.5 Preparation of b-5

a4 was added to a mixture of intermediate b-4 in an organic solvent andin the presence of an amine. Ethylacetate, acetonitrile, aceton,cyclohexane, chloroform and toluene are examples of suitable organicsolvents. Amines are suitably selected from e.g. triethylamine,di-isopropylamine. The mixture was stirred at RT for 6–18 hours andwashed with a solution of sodium bicarbonate and subsequently withbrine. The organic layer was dried over MgSO4 and the solvent wasevaporated. The compound was purified on silica gel.

3.6 Preparation of b-6

Reaction of intermediate b-5 with aldehydes (R_(5a)—C(═O)—H) results inthe generation of b-6. The reaction is suitably performed in alcohols inthe presence of an organic base e.g. pipiridine and at temperaturesranging from 65–100° C.

4. Preparation of Compound 7

4.1 Preparation of d-2.

The mixture of 76.9 g of intermediate d-1 in MeOH and 5 g of Pd/C 10%was stirred overnight in a hydrogen atmosphere. The mixture was filteredusing a filter such as celite and the solvent was evaporated to yield 48g (96%) of intermediate d-2 (tert-butylN-[3-amino-2-hydroxy-4-plenylbutyl]-N-isobutylcarbamate).

4.2 Preparation of d-3.

To a mixture of 7 g of intermediate d-2 in 300 ml of dichloromethane(DCM) was added 5.63 g of1-[[(3R,3aS,6aR)-hexahydrofuro[2,3-b]furan-3-yl]oxycarbonyloxy]-2,5-pyrrolidinedione(prepared according to the procedure described in WO9967417) and 2.1 gof triethylamine. The reaction mixture was stirred overnight at RT andthe solvent evaporated. The compound was purified on silica gel yielding9 g (88%) of intermediate c-3 (Hexahydrofuro[2,3-b]furan-3-ylN-{1-benzyl-3-[(tertbutoxycarbonyl)(isobutyl)amino]-2-hydroxypropyl}carbamate).

4.3 Preparation of d-4.

To a mixture of 9 g of intermediate d-3 in 200 ml of ethanol was addeddrop wise a solution of hydrochloric acid (e.g. 6N HCl) in isopropanol.The mixture was stirred over night at RT. 300 ml ethylacetate was addedand the mixture was washed with sodium bicarbonate solution 3 times andwith brine. The organic layer was dried over MgSO4 and concentrated toyield 5.5 g (77%) of intermediate d-4 (Hexahydrofuro[2,3-b]furan-3-ylN-[1-benzyl-2-hydroxy-3-(isobutylamino)propyl]carbamate.

4.4 Preparation of d-5

To a mixture of 3.34 g of compound d-4 in DCM 100 ml and 1.72 g triethylamine, 2.4 g 2-oxo-2,3-dihydro-1H-indole-5-sulfonyl chloride was added.The mixture was stirred at room temperature for 12 hours and washed witha solution of sodium bicarbonate and with brine. The organic layer wasdried over MgSO4 and the solvent was removed. The compound was purifiedon silica gel yielding 4 g (80%) of intermediate c-5(Hexahydrofuro[2,3-b]furan-3-ylN-(1-benzyl-2-hydroxy-3-{isobutyl[(2-oxo-2,3-dihydro-1H-indol-5-yl)sulfonyl]amino}propyl}carbamate)(compound21).

4.5 Preparation of d-6 (Compound 7)

To a mixture of 1 g of intermediate d-5 in 40 ml of ethanol and 217 mgpiperidine, 206 mg furfuraldehyd was added. The mixture was stirred at85° C. for 6 hours. Water was added and the mixture was extracted withethyl acetate. The organic layer was dried over MgSO4 and the solventwas removed. The compound was purified on silica gel yielding 1.1 g(95%) of compound 7 (d-6)(Hexahydrofuro[2,3-b]furan-3-ylN-{1-benzyl-3-[({3-[(E)-2-furylmethylidene]-2-oxo-2,3-dihydro-1H-indol-5-yl}sulfonyl)(isobutyl)amino]-2-hydroxypropyl}carbamate) in 70/30 E/Z mixtureobserved by NMR.

The compounds of formula (I) may also be converted to the correspondingN-oxide forms following art-known procedures for converting a trivalentnitrogen into its N-oxide form. Said N-oxidation reaction may generallybe carried out by reacting the starting material of formula (I) with anappropriate organic or inorganic peroxide. Appropriate inorganicperoxides comprise, for example, hydrogen peroxide, alkali metal orearth alkaline metal peroxides, e.g. sodium peroxide, potassiumperoxide; appropriate organic peroxides may comprise peroxy acids suchas, for example, benzenecarboperoxoic acid or halo substitutedbenzenecarboperoxoic acid, e.g. 3-chloro-benzenecarboperoxoic acid,peroxoalkanoic acids, e.g. peroxoacetic acid, alkylhydroperoxides, e.g.tert-butyl hydroperoxide. Suitable solvents are, for example, water,lower alkanols, e.g. ethanol and the like, hydrocarbons, e.g. toluene,ketones, e.g. 2-butanone, halogenated hydrocarbons, e.g.dichloromethane, and mixtures of such solvents.

The present compounds can thus be used in animals, preferably inmammals, and in particular in humans as pharmaceuticals per se, inmixtures with one another or in the form of pharmaceutical preparations.

Furthermore, the present invention relates to pharmaceuticalpreparations which as active constituents contain an effective dose ofat least one of the compounds of formula (I) in addition to customarypharmaceutically innocuous excipients and auxiliaries. Thepharmaceutical preparations normally contain 0.1 to 90% by weight of acompound of formula (I). The pharmaceutical preparations can be preparedin a manner known per se to one of skill in the art. For this purpose,at least one of a compound of formula (I), together with one or moresolid or liquid pharmaceutical excipients and/or auxiliaries and, ifdesired, in combination with other pharmaceutical active compounds, arebrought into a suitable administration form or dosage form which canthen be used as a pharmaceutical in human medicine or veterinarymedicine.

Pharmaceuticals which contain a compound according to the invention canbe administered orally, parenterally, e.g., intravenously, rectally, byinhalation, or topically, the preferred administration being dependenton the individual case, e.g., the particular course of the disorder tobe treated. Oral administration is preferred.

The person skilled in the art is familiar on the basis of his expertknowledge with the auxiliaries which are suitable for the desiredpharmaceutical formulation. Beside solvents, gel-forming agents,suppository bases, tablet auxiliaries and other active compoundcarriers, antioxidants, dispersants, emulsifiers, antifoams, flavorcorrigents, preservatives, solubilizers, agents for achieving a depoteffect, buffer substances or colorants are also useful.

Due to their favorable pharmacological properties, particularly theiractivity against multi-drug resistant HIV protease enzymes, thecompounds of the present invention are useful in the treatment ofindividuals infected by HIV and for the prophylaxis of theseindividuals. In general, the compounds of the present invention may beuseful in the treatment of warm-blooded animals infected with viruseswhose existence is mediated by, or depends upon, the protease enzyme.Conditions which may be prevented or treated with the compounds of thepresent invention, especially conditions associated with HIV and otherpathogenic retroviruses, include AIDS, AIDS-related complex (ARC),progressive generalized lymphadenopathy (PGL), as well as chroniccentral nervous system (CNS) diseases caused by retroviruses, such as,for example HIV mediated dementia and multiple sclerosis.

The compounds of the present invention or any subgroup thereof maytherefore be used as medicines against above-mentioned conditions. Saiduse as a medicine or method of treatment comprises the systemicadministration to HIV-infected subjects of an amount effective to combatthe conditions associated with HIV and other pathogenic retroviruses,especially HIV-1. Consequently, the compounds of the present inventioncan be used in the manufacture of a medicament useful for treatingconditions associated with HIV and other pathogenic retroviruses, inparticular medicaments useful for treating patients infected withmulti-drug resistant HIV virus.

In a preferred embodiment, the invention relates to the use of acompound of formula (I) or any subgroup thereof in the manufacture of amedicament for treating or combating infection or disease associatedwith multi-drug resistant retrovirus infection in a mammal, inparticular HIV-1 infection. Thus, the invention also relates to a methodof treating a retroviral infection, or a disease associated withmulti-drug resistant retrovirus infection comprising administering to amammal in need thereof an effective amount of a compound of formula (I)or a subgroup thereof.

In another preferred embodiment, the present invention relates to theuse of formula (I) or any subgroup thereof in the manufacture of amedicament for inhibiting a protease of a multi-drug resistantretrovirus in a mammal infected with said retrovirus, in particularHIV-1 retrovirus.

In another preferred embodiment, the present invention relates to theuse of formula (I) or any subgroup thereof in the manufacture of amedicament for inhibiting multi-drug resistant retroviral replication,in particular HIV-1 replication.

The compounds of the present invention may also find use in inhibitingex vivo samples containing HIV or expected to be exposed to HIV. Hence,the present compounds may be used to inhibit HIV present in a body fluidsample which contains or is suspected to contain or be exposed to HIV.

Also, the combination of an antiretroviral compound and a compound ofthe present invention can be used as a medicine. Thus, the presentinvention also relates to a product containing (a) a compound of thepresent invention, and (b) another antiretroviral compound, as acombined preparation for simultaneous, separate or sequential use intreatment of retioviral infections, in particular, in the treatment ofinfections with multi-drug resistant retroviruses. Thus, to combat ortreat HIV infections, or the infection and disease associated with HIVinfections, such as Acquired Immunodeficiency Syndrome (AIDS) or AIDSRelated Complex (ARC), the compounds of this invention may beco-administered in combination with for instance, binding inhibitors,such as, for example, dextran sulfate, suramine, polyanions, solubleCD4, PRO-542, BMS-806; fusion inhibitors, such as, for example, T20,T1249, 5-helix, D-peptide ADS-J1; co-receptor binding inhibitors, suchas, for example, AMD 3100, AMD-3465, AMD7049, AMD3451 (Bicyclams), TAK779; SHC-C (SCH351125), SHC-D, PRO-140RT inhibitors, such as, forexample, foscarnet and prodrugs; nucleoside RTIs, such as, for example,AZT, 3TC, DDC, DDI, D4T, Abacavir, FTC, DAPD, dOTC, DPC 817; nucleotideRTIs, such as, for example, PMEA, PMPA (tenofovir); NNRTIs, such as, forexample, nevirapine, delavirdine, efavirenz, 8 and 9-Cl TIBO(tivirapine), loviride, TMC-125, dapivirine, MKC-442, UC 781, UC 782,Capravirine, DPC 961, DPC963, DPCO82, DPCO83, calanolide A, SJ-1366,TSAO, 4″-deaminated TSAO, MV150, MV026048; RNAse H inhibitors, such as,for example, SP1093V, PD126338; TAT inhibitors, such as, for example,RO-5-3335, K12, K37; integrase inhibitors, such as, for example, L708906, L 731988, S-1360; protease inhibitors, such as, for example,amprenavir and prodrug GW908, ritonavir, nelfinavir, saquinavir,indinavir, lopinavir, palinavir, BMS 186316, atazanavir, DPC 681, DPC684, tipranavir, AG1776, mozenavir, GS3333, KNI-413, KNI-272, L754394,L756425, LG-71350, PD161374, PD173606, PD177298, PD178390, PD178392, PNU140135, TMC-114, maslinic acid, U-140690; glycosylation inhibitors, suchas, for example, castanospermine, deoxynojirimycine.

The combination may provide a synergistic effect, wherein viralinfectivity and its associated symptoms may be prevented, substantiallyreduced, or eliminated completely.

The compounds of the present invention may also be administered incombination with immunomodulators (e.g., bropirimine, anti-human alphainterferon antibody, IL-2, methionine enkephalin, interferon alpha, andnaltrexone) with antibiotics (e.g., pentamidine isothiorate) cytokines(e.g. Th2), modulators of cytokines, chemokines or the receptors thereof(e.g. CCR5) or hormones (e.g. growth hormone) to ameliorate, combat, oreliminate HIV infection and its symptoms. Such combination therapy indifferent formulations, may be administered simultaneously, sequentiallyor independently of each other. Alternatively, such combination may beadministered as a single formulation, wherein the active ingredients arereleased from the formulation simultaneously or separately.

The compounds of the present invention may also be administered incombination with modulators of the metabolization following applicationof the drug to an individual. These modulators include compounds thatinterfere with the metabolization at cytochromes, such as cytochromeP450. It is known that several isoenzymes exist of cytochrome P450, oneof which is cytochrome P450 3A4. Ritonavir is an example of a modulatorof metabolization via cytochrome P450. Such combination therapy indifferent formulations, may be administered simultaneously, sequentiallyor independently of each other. Alternatively, such combination may beadministered as a single formulation, wherein the active ingredients arereleased from the formulation simultaneously or separately. Suchmodulator may be administered at the same or different ratio as thecompound of the present invention. Preferably, the weight ratio of suchmodulator vis-à-vis the compound of the present invention(modulator:compound of the present invention) is 1:1 or lower, morepreferable the ratio is 1:3 or lower, suitably the ratio is 1:10 orlower, more suitably the ratio is 1:30 or lower.

For an oral administration form, compounds of the present invention aremixed with suitable additives, such as excipients, stabilizers or inertdiluents, and brought by means of the customary methods into thesuitable administration forms, such as tablets, coated tablets, hardcapsules, aqueous, alcoholic, or oily solutions. Examples of suitableinert carriers are gum arabic, magnesia, magnesium carbonate, potassiumphosphate, lactose, glucose, or starch, in particular, corn starch. Inthis case the preparation can be carried out both as dry and as moistgranules. Suitable oily excipients or solvents are vegetable or animaloils, such as sunflower oil or cod liver oil. Suitable solvents foraqueous or alcoholic solutions are water, ethanol, sugar solutions, ormixtures thereof. Polyethylene glycols and polypropylene glycols arealso useful as further auxiliaries for other administration forms.

For subcutaneous or intravenous administration, the active compounds, ifdesired with the substances customary therefor such as solubilizers,emulsifiers or further auxiliaries, are brought into solution,suspension, or emulsion. The compounds of formula (I) can also belyophilized and the lyophilizates obtained used, for example, for theproduction of injection or infusion preparations. Suitable solvents are,for example, water, physiological saline solution or alcohols, e.g.ethanol, propanol, glycerol, in addition also sugar solutions such asglucose or mannitol solutions, or alternatively mixtures of the varioussolvents mentioned.

Suitable pharmaceutical formulations for administration in the form ofaerosols or sprays are, for example, solutions, suspensions or emulsionsof the compounds of formula (I) or their physiologically tolerable saltsin a pharmaceutically acceptable solvent, such as ethanol or water, or amixture of such solvents. If required, the formulation can alsoadditionally contain other pharmaceutical auxiliaries such assurfactants, emulsifiers and stabilizers as well as a propellant. Such apreparation customarily contains the active compound in a concentrationfrom approximately 0.1 to 50%, in particular from approximately 0.3 to3% by weight.

In order to enhance the solubility and/or the stability of the compoundsof formula (I) in pharmaceutical compositions, it can be advantageous toemploy α-, β- or γ-cyclodextrins or their derivatives. Also co-solventssuch as alcohols may improve the solubility and/or the stability of thecompounds of formula (I) in pharmaceutical compositions. In thepreparation of aqueous compositions, addition salts of the subjectcompounds are obviously more suitable due to their increased watersolubility.

Appropriate cyclodextrins are α-, β- or γ-cyclodextrins (CDs) or ethersand mixed ethers thereof wherein one or more of the hydroxy groups ofthe anhydroglucose units of the cyclodextrin are substituted withC₁₋₆alkyl, particularly methyl, ethyl or isopropyl, e.g. randomlymethylated β-CD; hydroxyC₁₋₆alkyl, particularly hydroxyethyl,hydroxypropyl or hydroxybutyl; carboxyC₁₋₆alkyl, particularlycarboxymethyl or carboxyethyl; C₁₋₆alkyl-carbonyl, particularly acetyl;C₁₋₆alkyloxycarbonylC₁₋₆alkyl or carboxyC₁₋₆alkyloxyC₁₋₆alkyl,particularly carboxymethoxypropyl or carboxyethoxypropyl;C₁₋₆alkylcarbonyloxyC₁₋₆alkyl, particularly 2-acetyloxypropyl.Especially noteworthy as complexants and/or solubilizers are β-CD,randomly methylated β-CD, 2,6-dimethyl-β-CD, 2-hydroxyethyl-β-CD,2-hydroxyethyl-γ-CD, 2-hydroxypropyl-γ-CD and(2-carboxymethoxy)propyl-β-CD, and in particular 2-hydroxypropyl-β-CD(2-HP-β-CD).

The term mixed ether denotes cyclodextrin derivatives wherein at leasttwo cyclodextrin hydroxy groups are etherified with different groupssuch as, for example, hydroxy-propyl and hydroxyethyl.

An interesting way of formulating the present compounds in combinationwith a cyclodextrin or a derivative thereof has been described inEP-A-721,331. Although the formulations described therein are withantifungal active ingredients, they are equally interesting forformulating the compounds of the present invention. The formulationsdescribed therein are particularly suitable for oral administration andcomprise an antifungal as active ingredient, a sufficient amount of acyclodextrin or a derivative thereof as a solubilizer, an aqueous acidicmedium as bulk liquid carrier and an alcoholic co-solvent that greatlysimplifies the preparation of the composition. Said formulations mayalso be rendered more palatable by adding pharmaceutically acceptablesweeteners and/or flavors.

Other convenient ways to enhance the solubility of the compounds of thepresent invention in pharmaceutical compositions are described inW0-94/05263, WO 98/42318, EP-A-499,299 and WO 97/44014, all incorporatedherein by reference.

More in particular, the present compounds may be formulated in apharmaceutical composition comprising a therapeutically effective amountof particles consisting of a solid dispersion comprising (a) a compoundof formula (I), and (b) one or more pharmaceutically acceptablewater-soluble polymers.

The term “a solid dispersion” defines a system in a solid state (asopposed to a liquid or gaseous state) comprising at least twocomponents, wherein one component is dispersed more or less evenlythroughout the other component or components. When said dispersion ofthe components is such that the system is chemically and physicallyuniform or homogenous throughout or consists of one phase as defined inthermodynamics, such a solid dispersion is referred to as “a solidsolution”. Solid solutions are preferred physical systems because thecomponents therein are usually readily bioavailable to the organisms towhich they are administered.

The term “a solid dispersion” also comprises dispersions which are lesshomogenous throughout than solid solutions. Such dispersions are notchemically and physically uniform throughout or comprise more than onephase.

The water-soluble polymer in the particles is conveniently a polymerthat has an apparent viscosity of 1 to 100 mPa·s when dissolved in a 2%aqueous solution at 20° C. solution.

Preferred water-soluble polymers are hydroxypropyl methylcelluloses orHPMC. HPMC having a methoxy degree of substitution from about 0.8 toabout 2.5 and a hydroxypropyl molar substitution from about 0.05 toabout 3.0 are generally water soluble. Methoxy degree of substitutionrefers to the average number of methyl ether groups present peranhydroglucose unit of the cellulose molecule. Hydroxy-propyl molarsubstitution refers to the average number of moles of propylene oxidewhich have reacted with each anhydroglucose unit of the cellulosemolecule.

The particles as defined hereinabove can be prepared by first preparinga solid dispersion of the components, and then optionally grinding ormilling that dispersion. Various techniques exist for preparing soliddispersions including melt-extrusion, spray-drying andsolution-evaporation, melt-extrusion being preferred.

It may further be convenient to formulate the present compounds in theform of nanoparticles which have a surface modifier adsorbed on thesurface thereof in an amount sufficient to maintain an effective averageparticle size of less than 1000 nm.

Useful surface modifiers are believed to include those which physicallyadhere to the surface of the antiretroviral agent but do not chemicallybond to the antiretroviral agent.

Suitable surface modifiers can preferably be selected from known organicand inorganic pharmaceutical excipients. Such excipients include variouspolymers, low molecular weight oligomers, natural products andsurfactants. Preferred surface modifiers include nonionic and anionicsurfactants.

Yet another interesting way of formulating the present compoundsinvolves a pharmaceutical composition wherein the present compounds areincorporated in hydrophilic polymers and applying this mixture as a coatfilm over many small beads, thus yielding a composition with goodbioavailability which can conveniently be manufactured and which issuitable for preparing pharmaceutical dosage forms for oraladministration.

Said beads comprise (a) a central, rounded or spherical core, (b) acoating film of a hydrophilic polymer and an antiretroviral agent and(c) a seal-coating polymer layer.

Materials suitable for use as cores in the beads are manifold, providedthat said materials are pharmaceutically acceptable and have appropriatedimensions and firmness. Examples of such materials are polymers,inorganic substances, organic substances, and saccharides andderivatives thereof.

The route of administration may depend on the condition of the subject,co-medication and the like.

Another aspect of the present invention concerns a kit or containercomprising a compound of formula (I) in an amount effective for use as astandard or reagent in a test or assay for determining the ability of apotential pharmaceutical to inhibit HIV protease, HIV growth, or both.This aspect of the invention may find its use in pharmaceutical researchprograms.

The compounds of the present invention can be used in phenotypicresistance monitoring assays, such as known recombinant assays, in theclinical management of resistance developing diseases such as HIV. Aparticularly useful resistance monitoring system is a recombinant assayknown as the Antivirogram™. The Antivirogram™ is a highly automated,high throughput, second generation, recombinant assay that can measuresusceptibility, especially viral susceptibility, to the compounds of thepresent invention. (Hertogs K et al. Antimicrob Agents Chemother, 1998;42(2):269–276, incorporated by reference).

Interestingly, the compounds of the present invention may comprisechemically reactive moieties capable of forming covalent bonds tolocalized sites such that said compound have increased tissue retentionand half-lives. The term “chemically reactive group” as used hereinrefers to chemical groups capable of forming a covalent bond. Reactivegroups will generally be stable in an aqueous environment and willusually be carboxy, phosphoryl, or convenient acyl group, either as anester or a mixed anhydride, or an imidate, or a maleimidate therebycapable of forming a covalent bond with functionalities such as an aminogroup, a hydroxy or a thiol at the target site on for example bloodcomponents such as albumine. The compounds of the present invention maybe linked to maleimide or derivatives thereof to form conjugates.

The dose of the present compounds or of the physiologically tolerablesalt(s) thereof to be administered depends on the individual case and,as customary, is to be adapted to the conditions of the individual casefor an optimum effect. Thus it depends, of course, on the frequency ofadministration and on the potency and duration of action of thecompounds employed in each case for therapy or prophylaxis, but also onthe nature and severity of the infection and symptoms, and on the sex,age, weight co-medication and individual responsiveness of the human oranimal to be treated and on whether the therapy is acute orprophylactic. Customarily, the daily dose of a compound of formula (I)in the case of administration to a patient approximately 75 kg in weightis 1 mg to 1 g, preferably 3 mg to 0.5 g. The dose can be administeredin the form of an individual dose, or divided into several, e.g. two,three, or four, individual doses.

Experimental Part

Preparation of the compounds of formula (I) and their intermediates

TABLE 1 Compounds of the present invention prepared according to themethods described above. If no stereochemistry is indicated, thecompound is present as a racemic mixture. The wavy bond indicates thatthe R_(a) substituent may be in cis or trans position or in a mixturethereof.

NO R_(5a) pEC₅₀ W Stereochemistry/salts 1

8.5 —H (3R, 3aS, 6aR)/base 2

8.07 —H (3R, 3aS, 6aR)/base 3

7.94 —H (3R, 3aS, 6aR)/base 4

7.81 —H (3R, 3aS, 6aR)/base 5

7.78 —H (3R, 3aS, 6aR)/base 6

7.71 —H (3R, 3aS, 6aR)/base 7

7.71 —H (3R, 3aS, 6aR)/base 8

7.7 —H (3R, 3aS, 6aR)/base 9

7.64 —H (3R, 3aS, 6aR)/base 10

7.6 —H (3R, 3aS, 6aR)/base 11

7.36 —H (3R, 3aS, 6aR)/base 12

7.26 —H (3R, 3aS, 6aR)/base 13

7.25 —H (3R, 3aS, 6aR)/base 14

7.23 —H (—)/base 15

7.19 —H (3R, 3aS, 6aR)/base 16

7.15 —H (3R, 3aS, 6aR)/base 17

7.11 —H (3R, 3aS, 6aR)/base 18

6.57 —H (3R, 3aS, 6aR)/base 19

6.52 —PO₃H₂ (3R, 3aS, 6aR)/base 20

6.05 —H (3R, 3aS, 6aR)/base

Compound 21Antiviral Analyses:

The compounds of the present invention were examined for anti-viralactivity in a cellular assay. The assay demonstrated that thesecompounds exhibited potent anti-HIV activity against a wild typelaboratory HIV strain (HIV-1 strain LAI). The cellular assay wasperformed according to the following procedure.

Cellular Assay Experimental Method:

HIV- or mock-infected MT4 cells were incubated for five days in thepresence of various concentrations of the inhibitor. At the end of theincubation period, all HIV-infected cells have been killed by thereplicating virus in the control cultures in the absence of anyinhibitor. Cell viability is measured by measuring the concentration ofMTT, a yellow, water soluble tetrazolium dye that is converted to apurple, water insoluble formazan in the mitochondria of living cellsonly. Upon solubilization of the resulting formazan crystals withisopropanol, the absorbance of the solution is monitored at 540 nm. Thevalues correlate directly to the number of living cells remaining in theculture at the completion of the five day incubation. The inhibitoryactivity of the compound was monitored on the virus-infected cells andwas expressed as EC₅₀ and EC₉₀. These values represent the amount of thecompound required to protect 50% and 90%, respectively, of the cellsfrom the cytopathogenic effect of the virus. The toxicity of thecompound was measured on the mock-infected cells and was expressed asCC₅₀, which represents the concentration of compound required to inhibitthe growth of the cells by 50%. The selectivity index (SI) (ratioCC₅₀/EC₅₀) is an indication of the selectivity of the anti-HIV activityof the inhibitor. Wherever results are reported as e.g. pEC₅₀ or pCC₅₀values, the result is expressed as the negative logarithm of the resultexpressed as EC₅₀ or CC₅₀ respectively.

Antiviral Spectrum:

Because of the increasing emergence of drug resistant HIV strains, thepresent compounds were tested for their potency against clinicallyisolated HIV strains harboring several mutations (Table 2 and 3). Thesemutations are associated with resistance to protease inhibitors andresult in viruses that show various degrees of phenotypiccross-resistance to the currently commercially available drugs such asfor instance saquinavir, ritonavir, nelfinavir, indinavir andamprenavir.

TABLE 2 List of mutations present in the protease gene of the HIVstrains (A to F) used. A V003I, L010I, V032T, L033M, E035D, S037Y,S037D, M046I, R057R/K, Q058E, L063P, K070T, A071V, I072V, I084V, L089V BV003I, L010I, K020R, E035D, M036I, S037N, Q058E, I062V, L063P, A071V,I072M, G073S, V077I, I084V, I085V, L090M C V003I, L010I, I015V, L019I,K020M, S037N, R04IK, I054V, Q058E, L063P, A071V, I084V, L090M, I093L DV003I, L010L/I, I013V, L033I, E035D, M036I, M046L, K055R, R057K, L063P,I066F, A071V, I084V, N088D, L090M E V003I, L010I, V011I, A022V, L024I,E035D, M036I, S037T, R041K, I054V, I062V, L063P, A071V, I084V F L010F,M046I, M071V, I084VResults:

As a measure of the broad spectrum activity of the present compounds,the fold resistance (FR), defined as FR=EC₅₀(mutant strain)/EC₅₀(HIV-1strain LAI), was determined. Table 3 shows the results of the antiviraltesting in terms of fold resistance. As can be seen in this table, thepresent compounds are effective in inhibiting a broad range of mutantstrains: Column A FR value towards mutant A, Column B: FR towards mutantB, Column C: FR towards mutant C, Column D: FR towards mutant D, ColumnE: FR towards mutant E, Column F: FR towards mutant F. The toxicity(Tox) is expressed as the pCC₅₀ value as determined with mocktransfected cells. Column WT displays the pEC50 value against wild typeHIV-LAI strain.

TABLE 3 Results of the toxicity testing and the resistance testingagainst mutant strains A to F (expressed as FR). No A B C D E F Tox WT 14.3 8.7 2.1 2.0 6.2 10 4.9 8.5 2 1.7 3.6 1 3.8 3.1 3.9 4.7 8.01 3 3.03.8 2.6 3.0 7.1 6.8 4 7.9 4 2.3 1.9 1.7 1.9 2.4 2.0 4 7.8 5 1.9 8.3 2.02.0 4.2 6.5 4.2 7.8 6 2.5 7.1 1.6 1.4 2.0 7.9 4.3 7.7 7 1.8 2.6 1.7 2.45.9 1.9 4.1 7.7 8 1.7 5.0 1.5 1.5 2.0 1.7 4.2 7.7 9 1.3 6.2 2.0 1.9 3.06.3 4.2 7.6 10 1.4 1.3 1.3 1.3 1.5 2.0 4 7.6 11 1.5 4.7 1.4 3.4 3.4 3.54 7.4 21 1.0 1.1 0.7  0.33  0.56 1.2 4.0 6.8In Vitro Pharmacokinetic Studies

The permeability of different compounds is evaluated according to aCaco-2 test protocol as described by Augustijns et al. (Augustijns etal. (1998). Int. J. of Pharm, 166, 45–54) whereby, Caco-2 cells at cellpassage number between 32 and 45 are grown in 24-well cell cultureplates for 21 to 25 days. The integrity of the cell monolayer is checkedby measuring the transepithelial electrical resistance (TEER). The testis performed at pH 7.4 and at 100 μM donor compound concentration.

The equilibrium solubility in simulated gastrointestinal solutions underthermodynamic conditions is a good measure for the solubility profile ofthe compound in the stomach and the different parts of the intestine.Simulated gastric fluid (SGF) (without pepsin) is set at pH of 1.5.Simulated intestinal fluids (SIF) (without bile salts) are set at pH 5,pH 6.5, pH 7 and pH 7.5. The experimental protocol uses 96-wellflat-bottom microplates in which 1 mg of compound is added per well(stock solution in methanol) and evaporated to dryness. The compoundsare resolubilized in SGF and SIF and incubated overnight on a horizontalshaking device at 37° C. After filtration, the compound concentrationsare determined by UV-spectrophotometry.

Oral Availability in the Rat and the Dog

The compounds are formulated as a 20 mg/ml solution or suspension inDMSO, PEG400 or cyclodextin 40% (CD40%) in water. For most experimentsin the rat, three dosing groups are formed: 1/single intraperitonealdose at 20 mg/kg using the DMSO formulation; 2/single oral dose at 20mg/kg using the PEG400 formulation and 3/single oral dose at 20 mg/kgusing the cyclodextrin formulation. Blood was sampled at regular timeintervals after dosing and drug concentrations in the serum weredetermined using a LC-MS bioanalytical method.

Boosting the Systemic Bioavailability

With the described type of compounds (protease-inhibitors), it is knownthat inhibition of the metabolic degradation processes can markedlyincrease the systemic availability by reducing the first-pass metabolismin the liver and the metabolic clearance from the plasma. This‘boosting’ principle can be applied in a clinical setting to thepharmacological action of the drug. This principle can be also exploredboth in the rat or the dog by simultaneous administration of a compoundthat inhibits the Cyt-p450 metabolic enzymes. Known blockers are forexample ritonavir and ketoconazole.

Protein Binding Analyses

Human serum proteins like albumin (HSA) or α-1 acid glycoprotein (AAG)are known to bind many drugs, resulting in a possible decrease in theeffectiveness of those compounds. In order to determine whether thepresent compounds would be adversely affected by this binding, theanti-HIV activity of the compounds was measured in the presence of humanserum, thus evaluating the effect of the binding of the proteaseinhibitors to those proteins.

MT4 cells are infected with HIV-1 LAI at a multiplicity of infection(MOI) of 0.001–0.01 CCID₅₀ (50% cell culture infective dose per cell,CCID₅₀). After 1 h incubation, cells are washed and plated into a 96well plate containing serial dilutions of the compound in the presenceof 10% FCS (foetal calf serum), 10% FCS+1 mg/ml AAG (α₁-acidglycoprotein), 10% FCS+45 mg/ml HSA (human serum albumin) or 50% humanserum (HS). After 5 or 6 days incubation, the EC₅₀ (50% effectiveconcentration in cell-based assays) is calculated by determining thecell viability or by quantifying the level of HIV replication. Cellviability is measured using the assay described above. Into a 96 wellplate containing serial dilutions of the compound in the presence of 10%FCS or 10% FCS+1 mg/ml AAG, HIV (wild type or resistant strain) and MT4cells are added to a final concentration of 200–250 CCID₅₀/well and30,000 cells/well, respectively. After 5 days of incubation (37° C., 5%CO₂), the viability of the cells is determined by the tetrazoliumcolorimetric MTT (3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazoliumbromide) method (Pauwels et al. J. Virol. Methods 1988, 20, 309321).

Formulation

Active ingredient, in casu a compound of formula (I), was dissolved inorganic solvent such as ethanol, methanol or methylene chloride,preferably, a mixture of ethanol and methylene chloride. Polymers suchas polyvinylpyrrolidone copolymer with vinyl acetate (PVP-VA) orhydroxypropylmethylcellulose (HPMC), typically 5 mPa·s, were dissolvedin organic solvents such as ethanol, methanol methylene chloride.Suitably the polymer was dissolved in ethanol. The polymer and compoundsolutions were mixed and subsequently spray dried. The ratio ofcompound/polymer was selected from 1/1 to 1/6. Intermediate ranges were1/1.5 and 1/3. A suitable ratio was 1/6. The spraydried powder, a soliddispersion, is subsequently filled in capsules for administration. Thedrug load in one capsule ranges between 50 and 100 mg depending on thecapule size used.

Film-Coated Tablets

Preparation of Tablet Core

A mixture of 100 g of active ingredient, in casu a compound of formula(I), 570 g lactose and 200 g starch was mixed well and thereafterhumidified with a solution of 5 g sodium dodecyl sulfate and 10 gpolyvinylpyrrolidone in about 200 ml of water. The wet powder mixturewas sieved, dried and sieved again. Then there was added 100 gmicrocrystalline cellulose and 15 g hydrogenated vegetable oil. Thewhole was mixed well and compressed into tablets, giving 10.000 tablets,each comprising 10 mg of the active ingredient.

Coating

To a solution of 10 g methylcellulose in 75 ml of denaturated ethanolthere was added a solution of 5 g of ethylcellulose in 150 ml ofdichloromethane. Then there were added 75 ml of dichloromethane and 2.5ml 1,2,3-propanetriol. 10 g of polyethylene glycol was molten anddissolved in 75 ml of dichloromethane. The latter solution was added tothe former and then there were added 2.5 g of magnesium octadecanoate, 5g of polyvinylpyrrolidone and 30 ml of concentrated color suspension andthe whole was homogenated. The tablet cores were coated with the thusobtained mixture in a coating apparatus.

1. A compound having the formula

an N-oxide, salt, stereoisomeric form, racemic mixture, prodrug, orester thereof, wherein R₁ and R₈ are, each independently, hydrogen,C₁₋₆alkyl, C₂₋₆alkenyl, arylC₁₋₆alkyl, C₃₋₇cycloalkyl,C₃₋₇cycloalkylC₁₋₆alkyl, aryl, Het¹, Het¹C₁₋₆alkyl, Het², orHet²C₁₋₆alkyl; R₁ may also be a radical of formula

wherein R₉, R_(10a) and R_(10b) are, each independently, hydrogen,C₁₋₄alkyloxycarbonyl, carboxyl, aminocarbonyl, mono- ordi(C₁₋₄alkyl)aminocarbonyl, C₃₋₇cycloalkyl, C₂₋₆alkenyl, C₂₋₆alkynyl orC₁₋₆alkyl optionally substituted with aryl, Het¹, Het², C₃₋₇cycloalkyl,C₁₋₄alkyloxycarbonyl, carboxyl, aminocarbonyl, mono- ordi(C₁₋₄alkyl)aminocarbonyl, aminosulfonyl, C₁₋₄alkylS(O)_(t), hydroxy,cyano, halogen or amino optionally mono- or disubstituted where thesubstituents are each independently selected from C₁₋₆alkyl, aryl,arylC₁₋₄alkyl, C₃₋₇cycloalkyl, C₃₋₇cycloalkylC₁₋₄alkyl, Het¹, Het²,Het¹C₁₋₄alkyl and Het²C₁₋₄alkyl; wherein R₉, R_(10a) and the carbonatoms to which they are attached may also form a C₃₋₇cycloalkyl radical;when L is —O—C₁₋₆alkanediyl-C(═O)— or —NR₈—C₁₋₆alkanediyl-C(═O)—, thenR₉ may also be oxo; R_(11a) is hydrogen, C₂₋₆alkenyl, C₂₋₆alkynyl,C₃₋₇cycloalkyl, aryl, aminocarbonyl optionally mono- or disubstituted,aminoC₁₋₄alkylcarbonyloxy optionally mono- or disubstituted,C₁₋₄alkyloxycarbonyl, aryloxycarbonyl, Het¹oxycarbonyl, Het²oxycarbonyl,aryloxycarbonylC₁₋₄alkyl, arylC₁₋₄alkyloxycarbonyl, C₁₋₄alkylcarbonyl,C₃₋₇cycloalkylcarbonyl, C₃₋₇cycloalkylC₁₋₄alkyloxycarbonyl,C₃₋₇cycloalkylcarbonyloxy, carboxylC₁₋₄alkylcarbonyloxy,C₁₋₄alkylcarbonyloxy, arylC₁₋₄alkylcarbonyloxy, arylcarbonyloxy,aryloxycarbonyloxy, Het¹carbonyl, Het¹carbonyloxy,Het¹C₁₋₄alkyloxycarbonyl, Het² carbonyloxy, Het²C₁₋₄alkylcarbonyloxy,Het²C₁₋₄alkyloxycarbonyloxy or C₁₋₆alkyl optionally substituted witharyl, aryloxy, Het² or hydroxy; wherein the substituents on the aminogroups are each independently selected from C₁₋₆alkyl, aryl,arylC₁₋₄alkyl, C₃₋₇cycloalkyl, C₃₋₇cycloalkylC₁₋₄alkyl, Het¹, Het²,Het¹C₁₋₄alkyl and Het²C₁₋₄alkyl; R_(11b) is hydrogen, C₃₋₇cycloalkyl,C₂₋₆alkenyl, C₂₋₆alkynyl, aryl, Het¹, Het² or C₁₋₆alkyl optionallysubstituted with halogen, hydroxy, C₁₋₄alkylS(═O)_(t), aryl,C₃₋₇cycloalkyl, Het¹, Het², amino optionally mono- or disubstitutedwhere the substituents are each independently selected from C₁₋₄alkyl,aryl, arylC₁₋₄alkyl, C₃₋₇cycloalkyl, C₃₋₇cycloalkylC₁₋₄alkyl, Het¹,Het², Het¹C₁₋₄alkyl and Het²C₁₋₄alkyl; wherein R_(11b) may be linked tothe remainder of the molecule via a sulfonyl group; t is, eachindependently, zero, 1 or 2; R₂ is hydrogen or C₁₋₆alkyl; L is —C(═O)—,—O—C(═O)—, —NR₈—C(═O)—, —O—C₁₋₆alkanediyl-C(═O)—,—NR₈—C₁₋₆alkanediyl-C(═O)—, —S(═O)₂—, —O—S(═O)₂—, —NR₈—S(═O)₂, whereineither the C(═O) group or the S(═O)₂ group is attached to the NR₂moiety; and wherein each independently the C₁₋₆alkanediyl moiety may beoptionally substituted with hydroxy, aryl, Het¹ or Het²; R₃ isC₁₋₆alkyl, aryl, C₃₋₇cycloalkyl, C₃₋₇cycloalkylC₁₋₄alkyl, orarylC₁₋₄alkyl; R₄ is hydrogen, C₁₋₄alkyloxycarbonyl, carboxyl,aminocarbonyl, mono- or di(C₁₋₄alkyl)aminocarbonyl, C₃₋₇cycloalkyl,C₂₋₆alkenyl, C₂₋₆alkynyl or C₁₋₆alkyl optionally substituted with one ormore substituents each independently selected from aryl, Het¹, Het²,C₃₋₇cycloalkyl, C₁₋₄alkyloxycarbonyl, carboxyl, aminocarbonyl, mono- ordi(C₁₋₄alkyl)aminocarbonyl, aminosulfonyl, mono- ordi(C₁₋₄alkyl)aminosulfonyl, C₁₋₄alkylS(═O)_(t), hydroxy, cyano, halogenor amino optionally mono- or disubstituted where the substituents areeach independently selected from C₁₋₄alkyl, aryl, arylC₁₋₄alkyl,C₃₋₇cycloalkyl, C₃₋₇cycloalkylC₁₋₄alkyl, Het¹, Het², Het¹C₁₋₄alkyl andHet²C₁₋₄alkyl;

R_(5a) and R_(5b) are, each independently, selected from hydrogen,C₁₋₆alkyl, C₂₋₆alkenyl, C₂₋₆alkynyl, C₃₋₇cycloalkyl, aryl, Het¹, Het²;wherein each of the substituents selected from C₁₋₆alkyl, C₂₋₆alkenyl,C₂₋₆alkynyl or C₃₋₇cycloalkyl, are optionally substituted on one or morecarbon atoms with a substituent independently selected from the groupconsisting of amino, mono- or di(C₁₋₄alkyl)amino, hydroxy, carboxyl,oxo, mercapto, halogen, cyanogen, nitro, C₁₋₄alkyloxy,C₁₋₄alkylcarbonyl, C₁₋₄alkylcarbonyloxy, C₁₋₄alkyloxycarbonyl, aryl,C₃₋₇cycloalkyl, Het¹, Het¹, C₁₋₄alkylcarbonyloxy, andC₁₋₄alkyloxycarbonyl; R₆ is hydrogen or C₁₋₆alkyl optionally substitutedon one or more carbon atoms with one or more substituents independentlyselected from the group consisting of amino, mono- ordi(C₁₋₄alkyl)amino, hydroxy, mercapto, oxo, cyanogen, nitro, halogen,carboxyl C₁₋₄alkyloxy, C₁₋₄alkylcarbonyl, C₁₋₄alkylcarbonyloxy,C₁₋₄alkyloxycarbonyl, C₃₋₇cycloalkyl, aryl, Het¹, Het²; wherein eachC₁₋₄alkyl may optionally be substituted by amino, mono- ordi(C₁₋₄alkyl)amino, hydroxy, mercapto, oxo, cyanogen, nitro, halogen, orcarboxyl.
 2. A compound according to claim 1 wherein R₁ is hydrogen,C₁₋₆alkyl, C₂₋₆alkenyl, arylC₁₋₆alkyl, C₃₋₇cycloalkyl,C₃₋₇cycloalkylC₁₋₆alkyl, aryl, Het¹, Het¹C₁₋₆alkyl, Het², orHet²C₁₋₆alkyl; wherein Het¹ is a monocyclic or bicyclic heterocyclehaving 5 to 10 ring members, which contains one or more heteroatom ringmembers each independently selected from nitrogen, oxygen or sulfur andwhich is optionally substituted on one or more carbon atoms.
 3. Acompound according to claim 1 wherein L is —O—C₁₋₆alkanediyl-C(═O)—. 4.A compound according to claim 1 wherein R_(5a) and R_(5b) are eachindependently selected from the group consisting of aryl, Het¹, Het² andC₁₋₆alkyl optionally substituted on one or more atoms with a substituentindependently selected from the group consisting of amino, hydroxy,carboxyl, oxo, sulfhydryl, halogen, nitro, cyanogen, C₁₋₄alkyl,aminoC₁₋₄alkyl, hydroxyC₁₋₄alkyl, haloC₁₋₄alkyl, C₁₋₄alkyloxy,C₁₋₄alkylcarbonyl, C₁₋₄alkylcarbonyloxy, C₁₋₄alkyloxycarbonyl,C₁₋₄alkylcarbonyloxyC₁₋₄alkyl, C₁₋₄alkyloxycarbonylC₁₋₄alkyl, aryl,C₃₋₇cycloalkyl, Het¹ and Het²; and R₆ is hydrogen.
 5. A compoundselected from the group consisting of:(1-Benzyl-2-hydroxy-3-{isobutyl-[2-oxo-3-(1H-pyrrol-2-ylmethylene)-2,3-dihydro-1H-indole-5-sulfonyl]-amino}-propyl)-carbamicacid hexahydro-furo[2,3-b]furan-3-yl ester,(1-Benzyl-2-hydroxy-3-{isobutyl-[3-(5-methyl-furan-2-ylmethylene)-2-oxo-2,3-dihydro-1H-indole-5-sulfonyl]-amino}-propyl)-carbamicacid hexahydro-furo[2,3-b]furan-3-yl ester,(1-Benzyl-2-hydroxy-3-{isobutyl-[3-(5-methyl-thiophen-2-ylmethylene)-2-oxo-2,3-dihydro-1H-indole-5-sulfonyl]-amino}-propyl)-carbamicacid hexahydro-furo[2,3-b]furan-3-yl ester,(1-Benzyl-2-hydroxy-3-{isobutyl-[3-(1-methyl-1H-pyrrol-2-ylmethylene)-2-oxo-2,3-dihydro-1H-indole-5-sulfonyl]-amino}-propyl)-carbamicacid hexahydro-furo[2,3-b]furan-3-yl ester,(1-Benzyl-3-{[3-(2-ethyl-butylidene)-2-oxo-2,3-dihydro-1H-indole-5-sulfonyl]-isobutyl-amino}-2-hydroxy-propyl)-carbamicacid hexahydro-furo[2,3-b]furan-3-yl ester,{1-Benzyl-2-hydroxy-3-[isobutyl-(3-isobutylidene-2-oxo-2,3-dihydro-1H-indole-5-sulfonyl)-amino]-propyl}-carbamicacid hexahydro-furo[2,3-b]furan-3-yl ester,{1-Benzyl-3-[(3-furan-2-ylmethylene-2-oxo-2,3-dihydro-1H-indole-5-sulfonyl)-isobutyl-amino]-2-hydroxy-propyl}-carbamicacid hexahydro-furo[2,3-b]furan-3-yl ester,(1-Benzyl-2-hydroxy-3-{isobutyl-[3-(4-methoxy-benzylidene)-2-oxo-2,3-dihydro-1H-indole-5-sulfonyl]-amino}-propyl)-carbamicacid hexahydro-furo[2,3-b]furan-3-yl ester,(1-Benzyl-2-hydroxy-3-{isobutyl-[2-oxo-3-(4-pyridin-2-yl-benzylidene)-2,3-dihydro-1H-indole-5-sulfonyl]-amino}-propyl)-carbamicacid hexahydro-furo[2,3-b]furan-3-yl ester,(1-Benzyl-2-hydroxy-3-{[3-(4-hydroxy-3,5-dimethyl-benzylidene)-2-oxo-2,3-dihydro-1H-indole-5-sulfonyl]-isobutyl-amino}-propyl)-carbamicacid hexahydro-furo[2,3-b]furan-3-yl ester,(1-Benzyl-3-{[3-(4-dimethylamino-benzylidene)-2-oxo-2,3-dihydro-1H-indole-5-sulfonyl]-isobutyl-amino}-2-hydroxy-propyl)-carbamicacid hexahydro-furo[2,3-b]furan-3-yl ester,(1-Benzyl-2-hydroxy-3-{[3-(1H-indol-2-ylmethylene)-2-oxo-2,3-dihydro-1H-indole-5-sulfonyl]-isobutyl-amino}-propyl)-carbamicacid hexahydro-furo[2,3-b]furan-3-yl ester, Acetic acid5-(5-{[3-(hexahydro-furo[2,3-b]furan-3-yloxycarbonylamino)-2-hydroxy-4-phenyl-butyl]-isobutyl-sulfamoyl}-2-oxo-1,2-dihydro-indol-3-ylidenemethyl)-furan-2-ylmethylester,{1-Benzyl-3-[(3-benzylidene-2-oxo-2,3-dihydro-1H-indole-5-sulfonyl)-isobutyl-amino]-2-hydroxy-propyl}-carbamicacid hexahydro-furo[2,3-b]furan-3-yl ester,(1-Benzyl-3-{[3-(4-diethylamino-3-hydroxy-benzylidene)-2-oxo-2,3-dihydro-1H-indole-5-sulfonyl]-isobutyl-amino}-2-hydroxy-propyl)-carbamicacid hexahydro-furo[2,3-b]furan-3-yl ester,(1-Benzyl-2-hydroxy-3-{[3-(2-hydroxy-benzylidene)-2-oxo-2,3-dihydro-1H-indole-5-sulfonyl]-isobutyl-amino}-propyl)-carbamicacid hexahydro-furo[2,3-b]furan-3-yl ester,(1-Benzyl-2-hydroxy-3-{isobutyl-[3-(2-methoxy-benzylidene)-2-oxo-2,3-dihydro-1H-indole-5-sulfonyl]-amino}-propyl)-carbamicacid hexahydro-furo[2,3-b]furan-3-yl ester,(1-Benzyl-2-hydroxy-3-{[3-(4-hydroxy-3-methoxy-benzylidene)-2-oxo-2,3-dihydro-1H-indole-5-sulfonyl]-isobutyl-amino}-propyl)-carbamicacid hexahydro-furo[2,3-b]furan-3-yl ester,(1-Benzyl-3-{isobutyl-[3-(5-methyl-furan-2-ylmethylene)-2-oxo-2,3-dihydro-1H-indole-5-sulfonyl]-amino}-2-phosphonooxy-propyl)-carbamicacid hexahydro-furo[2,3-b]furan-3-yl ester,4-(5-{[3-(Hexahydro-furo[2,3-b]furan-3-yloxycarbonylamino)-2-hydroxy-4-phenyl-butyl]-isobutyl-sulfamoyl}-2-oxo-1,2-dihydro-indol-3-ylidenemethyl)-benzoicacid, and a N-oxides, salts and stereoisomeric forms thereof.
 6. Apharmaceutical composition, comprising an effective amount of at leastone compound as claimed in claim 1, and a pharmaceutically tolerableexcipient.
 7. A method of treating infection or disease associated withmulti-drug resistant human immunodeficiency virus (HIV) retrovirusinfection in a mammal, comprising administering an effective amount ofat least one compound according to claim 1 to said mammal.
 8. Apharmaceutical composition, comprising an effective amount of at leastone compound as claimed in claim 2 and a pharmaceutically tolerableexcipient.
 9. A method of treating infection or disease associated withmulti-drug resistant human immunodeficiency virus (HIV) retrovirusinfection in a mammal, comprising administering an effective amount ofat least one compound according to claim 2 to said mammal.
 10. Apharmaceutical composition, comprising an effective amount of at leastone compound as claimed in claim 5 and a pharmaceutically tolerableexcipient.
 11. A method of treating infection or disease associated withmulti-drug resistant human immunodeficiency virus (HIV) retrovirusinfection in a mammal, comprising administering an effective amount ofat least one compound according to claim 5 to said mammal.
 12. Apharmaceutical composition, comprising an effective amount of at leastone compound as claimed in claim 1 and a pharmaceutically tolerableexcipient.
 13. A pharmaceutical composition, comprising an effectiveamount of at least one compound as claimed in claim 3 and apharmaceutically tolerable excipient.
 14. A pharmaceutical composition,comprising an effective amount of at least one compound as claimed inclaim 4 and a pharmaceutically tolerable excipient.
 15. A pharmaceuticalcomposition, comprising an effective amount of at least one compound asclaimed in claim 6 and a pharmaceutically tolerable excipient.